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VARIATIONS IN CONIFEROUS WOOD MOISTURE ESTIMATION BY ELECTRICAL TECHNIQUES by I-CHEN WANG B.Sc. Taiwan P r o v i n c i a l Chung H s i n g U n i v e r s i t y , 1970  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Faculty of Forestry  We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o t h e r e q u i r e d  THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1975 i  standard  In p r e s e n t i n g t h i s  thesis  an advanced degree at  further  agree  fulfilment  of  the  requirements  the U n i v e r s i t y of B r i t i s h Columbia, I agree  the L i b r a r y s h a l l make it I  in p a r t i a l  freely  available  for  t h a t p e r m i s s i o n f o r e x t e n s i v e copying o f  of  this  representatives. thesis for  It  this  thesis  of  financial  g a i n s h a l l not be allowed without my  Forestry /  The U n i v e r s i t y o f B r i t i s h Columbia  2075 Wesbrook Place Vancouver, Canada V6T 1W5  Date  April io.\°ins  or  i s understood that copying o r p u b l i c a t i o n  written permission.  Department  that  r e f e r e n c e and study.  f o r s c h o l a r l y purposes may be granted by the Head of my Department by h i s  for  ABSTRACT E l e c t r i c a l m o i s t u r e m e t e r s have c e r t a i n a d v a n t a g e s over o t h e r t e c h n i q u e s f o r d e t e r m i n i n g wood m o i s t u r e c o n t e n t .  V a r i a b i l i t y associated  w i t h such meter measurements has n o t been t h o r o u g h l y  investigated.  This  s t u d y examined some sources o f t h i s v a r i a b i l i t y t h a t a r i s e between s p e c i e s , between t r e e s and w i t h i n stem w h i c h r e l a t e t o wood e l e c t r i c a l  properties.  Wood samples i n c l u d e d p o r t i o n s o f seven r e c e n t l y f e l l e d f u l l - t r e e coniferous logs.  T h i s p r o v i d e d c o m p a r i s o n a s : between s p e c i e s  (lodgepole  p i n e ( P i n u s c o n t o r t a v a r . l a t i f o l i a E n g e l m . ) , w e s t e r n w h i t e spruce  (Picea  g l a u c a (Moench.) V o s s . ) , D o u g l a s - f i r ( P s e u d o t s u g a m e n z i e s i i v a r . g l a u c a ( B e i s s n . ) F r a n c o ) and s u b a l p i n e f i r ( A b i e s l a s i o c a r p a (Hook.) N u t t l . ) ; w i t h i n s p e c i e s ( f o u r l o d g e p o l e p i n e ) ; and w i t h i n i n d i v i d u a l stem ( f o u r t o f i v e i n h e i g h t s e r i e s , two t o f i v e i n r a d i a l s e r i e s ) .  In a d d i t i o n , one  l o d g e p o l e p i n e stump d i s p l a y i n g r e a c t i o n wood was i n c l u d e d .  Direct current  r e s i s t a n c e ( D e l m h o r s t RC-1B) and p o w e r - l o s s ( M o i s t u r e R e g i s t e r , Model L) m e t e r s were u s e d t o e s t i m a t e m o i s t u r e .  R a d i a l specimens (2.5 cm x 2.5 cm x  40 cm) were s u b d i v i d e d i n t o f o u r 10 cm l e n g t h s and p l a c e d s i d e by s i d e t o expose r a d i a l o r t a n g e n t i a l f a c e s t h a t accommodated t h e p o w e r - l o s s m e t e r head.  T h i s p r o v i d e d a novel way f o r c o l l e c t i n g and r e p l i c a t i n g d a t a w i t h  r e g a r d t o p o s i t i o n w i t h i n stem, as w e l l as m i n i m i z i n g defect.  the influence of  Specimens were t e s t e d a t 21°C f o r nominal m o i s t u r e  levels  ("green", 19% and 12% f o r r e s i s t a n c e m e t e r , 19%, 12% and 6% f o r p o w e r - l o s s m e t e r ) and meter r e a d i n g s were compared w i t h c a l c u l a t e d  moistures.  D i r e c t c u r r e n t r e s i s t a n c e m o i s t u r e meter measurements d i d n o t a p p e a r t o be r e l a t e d t o wood s p e c i f i c g r a v i t y .  Between t r e e measurements w i t h i n  l o d g e p o l e p i n e showed l e s s v a r i a t i o n than measurements between t h e f o u r  ii  species.  Within tree height contributed l i t t l e to v a r i a t i o n , but r a d i a l -  d i r e c t i o n d i d p r o v i d e d i s c e r n i b l e v a r i a t i o n , e s p e c i a l l y a t low contents.  moisture  P r e c i s i o n o f t h e r e s i s t a n c e measurements was good, b u t a c c u r a c y  was poor. P o w e r - l o s s type m o i s t u r e m e t e r measurements were i n f l u e n c e d by s p e c i f i c gravity.  Regression  l i n e s o f m e t e r r e a d i n g s and m o i s t u r e c o n t e n t a p p r o a c h e d  quadratic f u n c t i o n s , with the notable exception o f D o u g l a s - f i r . equations  Regression  c o n t a i n i n g m o i s t u r e c o n t e n t , m o i s t u r e c o n t e n t s q u a r e d and s p e c i f i c  g r a v i t y as i n d e p e n d e n t v a r i a b l e s a c c o u n t e d f o r 92% o f the t o t a l v a r i a b i l i t y f o r a l l seven t r e e s s t u d i e d , and 96% among t h e f o u r l o d g e p o l e p i n e t r e e s . Between s p e c i e s v a r i a t i o n s i n p o w e r - l o s s m e t e r measurements were p r o m i n e n t and h i g h l y s i g n i f i c a n t . T h e r e were a l s o s i g n i f i c a n t d i f f e r e n c e s f o r between t r e e measurements.  Within tree height contributed l i t t l e , but  radial direction did contribute to variation.  Exposure o f r a d i a l o r tan-  g e n t i a l f a c e s gave s i g n i f i c a n t l y d i f f e r e n t r e a d i n g s . Better understanding  o f t h e c o n t r i b u t i o n o f such v a r i a b l e s c o u l d i n -  c r e a s e u s e f u l n e s s o f m o i s t u r e e s t i m a t i o n s by e l e c t r i c a l m e t e r s .  i ii  TABLE OF CONTENTS Page T I T L E PAGE .... ,  . . i;  ABSTRACT  i i  TABLE OF CONTENTS  iv  LIST OF TABLES ..."  vi  LIST OF FIGURES  ix  LIST OF APPENDICES  xi  ACKNOWLEDGMENTS  xii  1.0  INTRODUCTION  1  2.0  LITERATURE REVIEW  4  2.1  M o i s t u r e and i t s I n t e r a c t i o n w i t h Wood  4  2.1.1  Wood m o i s t u r e d e f i n i t i o n s  4  2.1.2  I n t e r a c t i o n between wood m o i s t u r e and electric properties  2.2  '7  E f f e c t o f Wood V a r i a b i l i t y on E l e c t r i c P r o p e r t i e s 2.2.1 2.2.2 2.2.3  Wood p h y s i c a l p r o p e r t i e s i n r e l a t i o n t o electrical properties Wood a n a t o m i c a l p r o p e r t i e s i n r e l a t i o n t o electrical properties Wood chemical c o m p o s i t i o n  10 H 13  in r e l a t i o n to  electrical properties 3.0 MATERIALS AND METHODS  16 21  3.1  Sample C o l l e c t i o n  21  3.2  Specimen P r e p a r a t i o n s  21  3.3  M o i s t u r e Measurements  22  3.3.1  Instruments  22  3.3.2  M o i s t u r e c o n d i t i o n i n g and measurement  23  3.3.3  Oven-drying  25  and c a l i b r a t i o n  and c a l c u l a t i o n s iv  Page 4 •0  5.0  RESULTS  «  *  t  t  t  t  *  «  «  t  »  «  t  »  t  $  »  «  ?  »  «  t  «  »  »  »  «  27  4.1  Specific Gravity  27  4.2  R e s i s t a n c e Type M o i s t u r e M e t e r . . . . .  28  4.3  Power-loss M e t e r  Discussion  , ,  28 , • 30  5.1  Moisture Contents  30  5.2  Specific Gravities . . . . . . . .  30  5.3  The Power F a c t o r  32  5.4  Moisture Meter V a r i a b l e s  32  5.4.1  Between s p e c i e s v a r i a b i l i t y  33  5.4.2  Between t r e e v a r i a b i l i t y  39  5.4.3  Within tree height v a r i a b i l i t y  40  5.4.4  Within tree radial v a r i a b i l i t y  41  5.4.5  Within tree anisotropy  46  5.4.6  C o m p r e s s i o n wood  47  5.5  R e g r e s s i o n s and Comparisons  5.6  F u r t h e r Work  , , , , 48 50  6.0  CONCLUSIONS  51  7.0  LITERATURE CITED  53  v  LIST OF TABLES  A n a l y s i s o f v a r i a n c e t a b l e f o r between s p e c i e s p o w e r - l o s s m e t e r measurements. L o d g e p o l e p i n e No. 4, l o d g e p o l e p i n e r e a c t i o n wood, w h i t e s p r u c e , D o u g l a s f i r and s u b a l p i n e f i r d a t a were used. . A n a l y s i s o f c o v a r i a n c e t a b l e f o r between s p e c i e s p o w e r - l o s s m e t e r measurements. S p e c i f i c g r a v i t y i s t h e c o v a r i a t e . Lodg p o l e p i n e No. 4, l o d g e p o l e p i n e r e a c t i o n wood, w h i t e s p r u c e , D o u g l a s - f i r and suba l p i n e f i r d a t a were used Analysis of variance table f o r within l o d g e p o l e p i n e r e g u l a r woods p o w e r - l o s s m e t e r measurements. Analysis of covariance table f o r within l o d g e p o l e p i n e r e g u l a r woods p o w e r - l o s s m e t e r measurements. C o v a r i a t e i s specific gravity. Analysis o f variance f o r lodgepole pine No. 1 p o w e r - l o s s m e t e r measurements. Analysis of covariance f o r lodgepole p i n e No. 1 p o w e r - l o s s m e t e r measurements Covariate is specific gravity Analysis o f variance table f o r lodgepole p i n e No. 2 p o w e r - l o s s m e t e r measurements Analysis of covariance f o r lodgepole p i n e No. 2 p o w e r - l o s s m e t e r measurements Covariate i s specific gravity Analysis o f variance table f o r lodgepole p i n e No. 3 p o w e r - l o s s meter measurements . Analysis of covariance f o r lodgepole p i n e No. 3 p o w e r - l o s s m e t e r measurements Covariate i s specific gravity. .... Analysis o f variance table f o r lodgepole p i n e No. 4 p o w e r - l o s s m e t e r measurements  Page T a b l e 12.  Analysis of covariance f o r lodgepole p i n e No. 4 power-loss m e t e r measurements. Covariate i s s p e c i f i c gravity  70  Analysis of variance table f o r lodgepole p i n e r e a c t i o n wood p o w e r - l o s s m e t e r measurements.  71  T a b l e 14.  Analysis o f variance table f o r white s p r u c e power-loss m e t e r measurements  72  T a b l e 15.  Analysis o f covariance f o r white spruce power-loss meter:, measurements. C o v a r i a t e is s p e c i f i c gravity  72  T a b l e 16.  Analysis o f variance t a b l e f o r Douglasf i r power-loss meter measurements  73  T a b l e 17.  Analysis of covariance f o r Douglas-fir p o w e r - l o s s m e t e r measurements. C o v a r i a t e is s p e c i f i c g r a v i t y  .73  Analysis of variance table f o r subalpinef i r p o w e r - l o s s meter measurements. .  74  Analysis of covariance f o r s u b a l p i n e - f i r p o w e r - l o s s m e t e r measurements. C o v a r i a t e is s p e c i f i c gravity  74  Comparison o f p o w e r - l o s s m o i s t u r e m e t e r ( M o i s t u r e R e g i s t e r , Model L) c o r r e c t i o n tables f o r lodgepole pine pooled data. M a n u f a c t u r e r s u p p l i e d d a t a and t h e t a b l e p r e p a r e d by Bramhall and Salamon (11) are given f o r comparison. Underlined data are extrapolated  .75  Comparison o f p o w e r - l o s s m o i s t u r e m e t e r ( M o i s t u r e R e g i s t e r , Model L) c o r r e c t i o n t a b l e s f o r w h i t e s p r u c e d a t a . Manufact u r e r s u p p l i e d t a b l e and t h e t a b l e p r e p a r e d by Bramhall and Salamon (11) a r e given f o r comparison. Underlined data are e x t r a p o l a t e d  .76  T a b l e 13.  T a b l e 18, T a b l e 19.  T a b l e 20.  T a b l e 21.  vi i  Page T a b l e 22.  T a b l e 23.  T a b l e 24.  Comparison o f p o w e r - l o s s m o i s t u r e meter ( M o i s t u r e R e g i s t e r , Model L) c o r r e c t i o n t a b l e s f o r D o u g l a s - f i r d a t a . Manufact u r e r s u p p l i e d t a b l e and the t a b l e p r e pared by Bramhall and Salamon (11) a r e g i v e n f o r c o m p a r i s o n . U n d e r l i n e d data are e x t r a p o l a t e d . . . . . . . . . . . . •  77  Comparison o f p o w e r - l o s s m o i s t u r e meter ( M o i s t u r e R e g i s t e r , Model L) c o r r e c t i o n t a b l e s f o r s u b a l p i n e f i r d a t a . Manufact u r e r s u p p l i e d t a b l e and the t a b l e p r e pared by Bramhall and Salamon (11) a r e given f o r comparison. Underlined data are e x t r a p o l a t e d  78  L i s t o f regression equations  79  viii  LIST OF FIGURES Page F i g 1.  Schematic diagram o f sample p r e p a r a t i o n and scheme o f measurements ... . . . ... .. ...  82  F i g 2.  S p e c i f i c g r a v i t y ( o v e n - d r y w e i g h t and "green" volume) v a r i a t i o n s among s p e c i e s . Lodgepole p i n e No. 4, White s p r u c e , Douglasf i r and s u b a l p i n e f i r sample s p e c i f i c g r a v i t i e s a t 5 h e i g h t l e v e l s and r a d i a l s e r i e s a r e p r e s e n t e d . Right-most p o i n t s a t each h e i g h t l e v e l a r e the sapwood samples. Number o f o b s e r v a t i o n s i s e i g h t f o r each point  83  F i g 3.  F i g 4.  F i g 5.  F i g 6.  S p e c i f i c g r a v i t y ( o v e n - d r y w e i g h t and "green" volume) v a r i a t i o n s among l o d g e p o l e p i n e t r e e s ( i n c l u d i n g compression wood) a t 5 h e i g h t l e v e l s and r a d i a l s e r i e s a r e p r e s e n t e d . Right-most p o i n t s a t each h e i g h t l e v e l a r e t h e sapwood samples. Number o f o b s e r v a t i o n i s e i g h t f o r each point . . .  .84  R e s i s t a n c e m o i s t u r e m e t e r measurements v s . m o i s t u r e c o n t e n t s (oven-dry b a s i s ) f o r between s p e c i e s comparison as l o d g e p o l e p i n e No. 4, w h i t e s p r u c e , Douglasf i r and s u b a l p i n e f i r . ( S o l i d l i n e s r e p r e s e n t heartwood samples and dashed l i n e s r e p r e s e n t sapwood samples. Symbols on l i n e s s e r v e t o d i s t r i n g u i s h between l i n e s and a r e n o t d a t a p o i n t s . )  .85  R e s i s t a n c e m o i s t u r e m e t e r measurements on l o d g e p o l e p i n e samples v s . m o i s t u r e c o n t e n t s (oven-dry b a s i s ) . ( S o l i d l i n e s r e p r e s e n t heartwood samples, and dashed l i n e s r e p r e s e n t sapwood samples  86  Graph showing t h e r e l a t i o n s h i p between power-loss meter r e a d i n g s and m o i s t u r e contents (oven-dry b a s i s ) o f lodgepole p i n e p o o l e d ( L l - 4 ) , l o d g e p o l e p i n e No. 4 (L 4 ) , w h i t e s p r u c e (W.S.), Douglasf i r (D.F.) and s u b a l p i n e f i r ( A . F . ) . (Symbols on r e g r e s s i o n l i n e s s e r v e t o d i s t i n g u i s h between l i n e s and a r e n o t data points.)  87  ix  Graph showing t h e r e l a t i o n s h i p between p o w e r - l o s s m e t e r r e a d i n g s and m o i s t u r e contents (oven-dry b a s i s ) o f lodgepole p i n e No. 1 (L 1)., L o d g e p o l e p i n e No. 2 (L 2 ) , l o d e p o l e p i n e No. 3 ( L 3 ) , l o d g e p o l e p i n e No. 4 (L 4) and l o d g e p o l e p i n e compression wood (LRW). (Symbols on l i n e s a r e not data p o i n t s . ) Graph showing t h e r e l a t i o n s h i p between power-loss meter r e a d i n g s and m o i s t u r e c o n t e n t s q u a r e d (oven-dry b a s i s ) o f l o d g e p o l e p i n e No. 4 ( L 4 ) , l o d g e p o l e p i n e p o o l e d ( L l - 4 ) , w h i t e s p r u c e (W.S.), D o u g l a s - f i r (D.F.) and s u b a l p i n e f i r ( A . F . ) . (Symbols on r e g r e s s i o n l i n e s s e r v e t o d i s t i n g u i s h between l i n e s and are not data points.) Graph showing t h e r e g r e s s i o n o f l o d g e p o l e p i n e t r e e power-lossrnmeter r e a d i n g s on m o i s t u r e c o n t e n t s q u a r e d (oven-dry b a s i s ) . These two v a r i a b l e s e x h i b i t q u a d r a t i c r e l a t i o n s h i p s . (Symbols on r e g r e s s i o n l i n e s s e r v e t o d i s t i n g u i s h between l i n e s and a r e n o t d a t a p o i n t s . ) Graph showing t h e r e l a t i o n s h i p between power-loss meter r e a d i n g s and m o i s t u r e content squared (oven-dry b a s i s ) o f lodgep o l e p i n e compression wood (LRW) and r e g u l a r woods (L 1 - 4 ) . (Symbols on regression lines serve to distinguish between l i n e s and a r e n o t data p o i n t s . ) .  LIST OF APPENDICES Page Appendix I,  Appendix I I .  Appendix I I I ,  Appendix IV.  Appendix V.  C h a r a c t e r i s t i c s o f sample t r e e stems s h o w - t o t a l stem l e n g t h , d i a m e t e r and segments a c c o r d i n g t o h e i g h t l e v e l (measured i n meters from stem b a s e ) .  92  Growth zone numbers i n t h e c e n t e r o f e a c h specimen c r o s s s e c t i o n . R a d i a l s e r i e s No. 1 r e p r e s e n t s corewood, No. 2 t o 4 r e p r e s e n t heartwood and No. 5 r e p r e s e n t s sapwood wood' z o n e s . . . .  93  C i r c u i t r y o f t h e p o w e r - l o s s m o i s t u r e meter ( M o i s t u r e R e g i s t e r ) . Where M i s t h e meter V i s a vacuum tube and X i s t h e s a m p l i n g e l e c t r o d e s . Adopted from Uyemura ( 8 8 ) . . . .  95  R e s i s t a n c e m o i s t u r e meter ( D e l m h o r s t RC-1B) measurements (MT) on wood samples from t r e e s o f t h e s t u d y compared t o ovend r y (OD) c a l c u l a t i o n s ; i n c l u d i n g nominal m o i s t u r e l e v e l (N MC), a t stem h e i g h t s ( H t . ) and f o r two r a d i a l r e p l i c a t i o n s (1-4 heartwood, 5 sapwood). O b s e r v a t i o n a r e 16 f o r each r e a d i n g a t 19 and 12% nominal m o i s t u r e l e v e l s , and 8 f o r each reading a t "green" c o n d i t i o n  96  P o w e r - l o s s m o i s t u r e meter ( M o i s t u r e R e g i s t e r , Model L) measurements ( M T - r a d i a l , M T - t a n g e n t i a l ) on wood samples from t r e e s o f t h e s t u d y compared t o oven-dry (OD) c a l c u l a t i o n s ; i n c l u d i n g nominal m o i s t u r e l e v e l s (N MC) a t stem h e i g h t s ( H t . ) and f o r two r a d i a l r e p l i c a t i o n s (1-4 heartwood, 5 sapwood). O b s e r v a t i o n s a r e 2 f o r each r e a d i n g  104  xi  ACKNOWLEDGMENTS  The a u t h o r w i s h e s t o e x p r e s s h i s g r a t i t u d e t o Dr. J . W. W i l s o n , P r o f e s s o r , F a c u l t y of F o r e s t r y , U n i v e r s i t y of B r i t i s h Columbia, f o r h i s guidance and s u p e r v i s i o n o f the t h e s i s . Thanks a r e due a l s o t o Mr. N o e l , M e r r i l l and Wanner Lumber Co., W i l l i a m s Lake, B. C ,  f o r h e l p i n s e c u r i n g the e x p e r i m e n t a l  materials;  t o Mr. M. Salamon, Research S c i e n t i s t , Western F o r e s t P r o d u c t s  Labora-  t o r y , V a n c o u v e r , f o r h i s s u g g e s t i o n s and use o f f a c i l i t i e s f o r m o i s t u r e meter c a l i b r a t i o n s ; and t o M e s s r s . U. Rumma and G. Bohnenkamp, T e c h n i c i a n s , F a c u l t y o f F o r e s t r y , f o r t h e i r a s s i s t a n c e i n numerous ways. S p e c i a l t h a n k s are due Dr. A. Kozak, P r o f e s s o r , F a c u l t y of F o r e s t r y , U n i v e r s i t y o f B r i t i s h C o l u m b i a , f o r h i s a d v i c e and s u g g e s t i o n s on s t a t i s t i c a l a n a l y s e s ; t o Mrs. K. H e j j a s , T e c h n i c i a n , f o r h e r e f f o r t s i n computer programming andf.data p l o t t i n g ; and t o Mr. R. C. Yang, f e l l o w  graduate  s t u d e n t , f o r help i n s e t t i n g up computer programs. F i n a n c i a l a s s i s t a n c e from t h e S c i e n c e S u b v e n t i o n  Program, Canadian  F o r e s t r y S e r v i c e and the U n i v e r s i t y o f B r i t i s h C o l u m b i a a r e g r a t e f u l l y acknowledged;, Dr. R. W. Kennedy, Western F o r e s t P r o d u c t s  Laboratory,  V a n c o u v e r , k i n d l y s e r v e d as L i a i s o n O f f i c i e r w i t h the C a n a d i a n F o r e s t r y Service.  xii  1.0  1  INTRODUCTION  M o i s t u r e l e v e l s e r i o u s l y a f f e c t s wood p r o p e r t i e s and u s e s .  In  a d d i t i o n , t h e r e a r e c o n s t a n t i n t e r a c t i o n s between ambient h u m i d i t y and J  wood which.changes  i t s moisture content.  In o p e r a t i o n s o f d r y i n g ,  m a c h i n i n g and wood t r e a t m e n t s , m o i s t u r e c o n t e n t has l a r g e i m p o r t a n c e .  It  a l s o a f f e c t s t r a n s p o r t a t i o n c o s t s t o t h e lumber and paper i n d u s t r i e s .  A  f a s t and r e l i a b l e means o f d e t e r m i n i n g m o i s t u r e c o n t e n t , i s t h e r e f o r e v i t a l f o r wood p r o d u c t q u a l i t y c o n t r o l . S e v e r a l c o n v e n t i o n a l means o f wood m o i s t u r e c o n t e n t d e t e r m i n a t i o n a r e used c u r r e n t l y . These i n c l u d e o v e n - d r y i n g , d i s t i l l a t i o n , t i t r a t i o n , hygTrome'-trctfcmethods and e l e c t r i c a l m o i s t u r e meters.  Most o f t h e s e methods  o p e r a t e o n l y on s m a l l sample q u a n t i t i e s , w h i l e some a r e d e s t r u c t i v e i n n a t u r e and a r e time consuming  t o u s e . Newer means o f m o i s t u r e d e t e r m i n a t i o n  have been s u g g e s t e d , such as b e t a r a y a d s o r p t i o n and n e u t r o n s c a t t e r i n g (66).  These a r e e i t h e r n o t d e v e l o p e d f o r p r a c t i c a l a p p l i c a t i o n o r r e q u i r e  e x p e n s i v e and b u l k y  equipment.  In 1972, Stamm (80) f i r s t s u g g e s t e d t h a t t h e r e l a t i o n s h i p between m o i s t u r e c o n t e n t and d i r e c t c u r r e n t r e s i s t a n c e o f wood c o u l d be used t o determine i t s moisture contnet.  S i n c e then numerous s t u d i e s have been made  i n t h i s f i e l d , and a v a r i e t y o f i n s t r u m e n t s have been d e v i s e d f o r e s t i m a t i n g moisture.  E l e c t r i c a l meters o f f e r t h e advantages o f s p e e d , economy,  m o b i l i t y n o n - d e s t r u c t i v e n e s s and r e a s o n a b l e a c c u r a c y , and have l i t t l e r e s t r i c t i o n on sample s i z e .  These b e n e f i t s p u t e l e c t r i c a l m o i s t u r e meters  i n f a v o u r o v e r o t h e r c o n v e n t i o n a l methods o f d e t e r m i n i n g m o i s t u r e , e s p e c i a l l y i n r e g a r d t o c o n t i n u o u s m o n i t o r i n g and a u t o m a t i c c o n t r o l . More r e c e n t l y , t h e t r e n d i s toward t h e use o f d i e l e c t r i c p r o p e r t i e s  2  to a s s e s s m o i s t u r e c o n t e n t .  Two types o f d i e l e c t r i c m o i s t u r e  meters,  c a p a c i t y and r a d i o - f r e q u e n c y p o w e r - l o s s . a r e i n u s e . These a r e more e f f e c t i v e i n a s s e s s i n g low m o i s t u r e , l e a v e no  p i n marks on t h e specimen,  a r e c a p a b l e o f c o n t i n u o u s measurements and do n o t depend on good c o n t a c t between t h e e l e c t r o d e s and specimen.  The meter r e a d i n g s a r e a f f e c t e d ,  however, by t h e specimen d e n s i t y which may cause s u b s t a n t i a l d e v i a t i o n s . The use o f h i g h f r e q u e n c y microwaves may a m e l i o r a t e t h i s s i t u a t i o n , as t h e r e i s l e s s i n t e r a c t i o n between specimen  d e n s i t y and t h e d i e l e c t r i c  p r o p e r t i e s a t high f r e q u e n c i e s . E x p l o r a t i o n s " i n ' d i e l e c t r i c p r o p e r t i e s o f wood have opened up some o t h e r p o s s i b l e a p p l i c a t i o n s . McLauchlen  e_t aj_. (55) have p a t t e r n e d a  d e v i c e u s i n g t h e d i e l e c t r i c a n i s o t r o p y t o measure the g r a i n a n g l e s o f wood.  Pande (68) s u g g e s t e d u s i n g t h e d i e l e c t r i c c o n s t a n t t o a s s e s s c e l l u -  lose c r y s t a l l i n i t y .  Venkateswaran ( 9 2 ) , a f t e r o b s e r v i n g a l i n e a r r e -  l a t i o n s h i p between t h e l i g n i n c o n t e n t o f wood and t h e d i e l e c t r i c c o n s t a n t , has commented on t h e p o s s i b i l i t y d f a p p l y i n g t h e s e p o l a r i z a t i o n p r o p e r t i e s t o measure l i g n i n c o n t e n t .  However, t h e c o m p l e x i t y o f wood and i t s o v e r -  l a p p i n g p o l a r i z a t i o n s p e c t r a demand more s t u d y b e f o r e p r a c t i c a l app l i c a t i o n s o f t h e s e d i s c o v e r i e s can be e s t a b l i s h e d . Although there are tables a v a i l a b l e f o r adjusting e l e c t r i c a l  moisture  m e t e r r e a d i n g s as r e g a r d s s p e c i e s , v e r y l i t t l e a t t e n t i o n has been p a i d t o o t h e r f a c e t s o f wood v a r i a b i l i t y .  I t was a purpose o f t h i s s t u d y t o  i n v e s t i g a g e t h e r e l a t i o n s h i p between e l e c t r i c a l m o i s t u r e m e t e r  performance  and some a s p e c t s o f wood o r i g i n , such as d i f f e r e n c e s between c o n i f e r o u s s p e c i e s , between stems o f t h e same s p e c i e s , and between h e i g h t l e v e l s , w o o d zones and a n i s o t r o p y w i t h i n t h e same stem. f o r f u r t h e r s t u d y , wood specimens  A n o t h e r purpose was t o r e c o g n i z e  v a r y i n g g r e a t l y from e s t a b l i s h e d norms.  3  C o m e r c i a l l y a v a i l a b l e d i r e c t c u r r e n t r e s i s t a n c e type and r a d i o f r e q u e n c y p o w e r - l o s s type m o i s t u r e meters were used i n t h e s t u d y .  This  f u l f i l l e d t h e i d e a o f p r a c t i c a l i t y , a l t h o u g h t h e p r e c i s i o n o f t h e s e may be l e s s s a t i s f a c t o r y than s o p h i s t i c a t e d l a b o r a t o r y i n s t r u m e n t s . Through a s p e c i a l s a m p l i n g scheme and specimen arrangement, a l l measurements were c a r r i e d o u t on c o m p a r a t i v e l y s m a l l samples.  This  a l l o w e d a n a l y s e s and p r e s e n t a t i o n o f d a t a i n ways n o t done p r e v i o u s l y .  4  2.0  LITERATURE REVIEW  r<  M o i s t u r e c o n t e n t i s one o f the most i m p o r t a n t wood p r o p e r t y p a r a meters.  I t has g r e a t s i g n i f i c a n c e on economic and t e c h n i c a l a s p e c t s o f  the m a t e r i a l u t i l i z a t i o n .  T h e r e f o r e , i t i s deemed a p p r o p r i a t e to ex-  amine f i r s t the d e f i n i t i o n and i n t e r a c t i o n o f m o i s t u r e on wood. 2.1 2.1.1  M o i s t u r e and i t s I n t e r a c t i o n w i t h Wood. , Wood m o i s t u r e d e f i n i t i o n s . The m o i s t u r e c o n t e n t o f a m a t e r i a l may be d e f i n e d i n a v a r i e t y o f  ways, dependinggon  the purpose o f d e f i n i t i o n and the f i e l d o f t e c h n o l o g y  t o which i t i s a p p l i e d . Most f r e q u e n t l y , m o i s t u r e c o n t e n t i s e x p r e s s e d by c a l c u l a t i o n based on o r i g i n a l w e i g h t ( r e l a t i v e m o i s t u r e c o n t e n t ) , whereas i n the wood and t e x t i l e i n d u s t r i e s , the c a l c u l a t i o n i s based on oven-dry weight (absolute moisture content).  I n - e i t h e r c a s e , the s e p a r a t i o n o f dry  m a t e r i a l p o r t i o n from w a t e r p o r t i o n and a c c u r a t e measurement o f a t l e a s t one o f them i s e s s e n t i a l i n d e t e r m i n i n g m o i s t u r e c o n t e n t ( 3 1 ) .  This is  m o s t l y done by o v e n - d r y i n g t h e m a t e r i a l a c c o r d i n g to c e r t a i n s p e c i f i c a t i o n s to obtain i t s dry weight ( 1 ) . V a r i o u s methods and i n s t r u m e n t s have been d e v i s e d to measure m o i s t u r e c o n t e n t o f wood based on the r e l a t i o n s h i p between m o i s t u r e c o n t e n t and c e r t a i n p h y s i c a l p r o p e r t i e s o f wood, b u t a l l t h e s e measurements have t o be c a l i b r a t e d a c c o r d i n g t o the d r y w e i g h t . and u n i v e r s a l d r y i n g method i s e v i d e n t .  The i m p o r t a n c e o f a p r o p e r  A c c o r d i n g l y , i t i s one o f the  central issues of moisture content d e f i n i t i o n (41).  Both o v e n - d r y i n g and  h i g h vacuum d r y i n g have the problem o f b e i n g time consuming.  A l s o , the  a c c u r a c y s u f f e r s when the wood c o n t a i n s v o l a t i l e s u b s t a n c e s l i k e f a t s and o i l s (41).  5  Wood i s a complex f i b r o u s m a t e r i a l m a i n l y composed o f h o l l o w , e l ongated c e l l s o r i e n t e d p a r a l l e l t o the l o n i t u d i n a l a x i s o f the t r e e . The c e l l w a l l s i n t u r n a r e formed by l a m i n a t i o n o f numerous t h i n l a y e r s . A l s o , wood has both c o l l o i d a l p r o p e r t i e s and an i n f i n i t e c a p i l l a r y pores.  number o f  In such an i n t r i c a t e m a t e r i a l , w a t e r i n t e r a c t s w i t h  wood s u b s t a n c e i n a c o m p l i c a t e d manner.  In a d d i t i o n to t h e s e c o m p l i c a t i o n s ,  i t i s commonly assume.dthat m o i s t u r e c o n t e n t r e f e r s t o a d e f i n i t e and impl i c i t l y defined quantity of moisture present in a material.  However,  much c a r e f u l s t u d y may be n e c e s s a r y i n o r d e r to be a b l e to d e f i n e m o i s t u r e c o n t e n t u s e f u l l y f o r any g i v e n p u r p o s e , o r t o i n t e r p r e t the r e s u l t s o b t a i n e d from a p a r t i c u l a r method o f measurement.  For i n s t a n c e , measure-  ments based on d i e l e c t r i c constant-.- have t o take i n t o c o n s i d e r a t i o n the g r e a t v a r i a b i l i t y o f w a t e r , which may a d j u s t c o n s t a n t s from 9 (bonded  water)  t o 81 ( b u l k , f r e e w a t e r ) ( 3 1 ) . Water may be h e l d i n wood i n d i f f e r e n t s t a t e s as a r e s u l t o f d i f f e r e n t modes o f i n t e r a c t i o n w i t h wood s u b s t a n c e .  These i n t e r a c t i o n s o f t e n a l t e r  the; p h y s i c a l and c h e m i c a l p r o p e r t i e s o f both w a t e r and wood.  Most  a p p a r e n t o f a l l , f o r example, a r e the s o r p t i o n i s o t h e r m and d i m e n s i o n a l change o f wood ( 2 2 ) .  I t i s d i f f i c u l t t o d i f f e r e n t i a t e between d i f f e r e n t  s t a t e s o f w a t e r i n wood, a l t h o u g h i t i s c l a s s i f i e d i n t o t h r e e types a c c o r d i n g t o one system.  Based on the bonding f o r c e between w a t e r m o l e c u l e s  and wood s u b s t a n c e , t h e r e are c h e m i c a l , p h y s i c o - c h e m i c a l and p h y s i c a l bondings ( 3 1 ) . C h e m i c a l l y bonded w a t e r s , such as h y d r a t e s and c r y s t a l l i n e compounds, a r e a b s o r b e d on to the m o l e c u l a r s t r u c t u r e t o form a s o l i d s o l u t i o n , and become a p o r t i o n o f the wood c o n s t i t u t i o n , hence the term "water o f consitution".  Stamm (82) c o n s i d e r e d t h i s p o r t i o n not w a t e r a t a l l but h y d r o x y l  groups t h a t s p l i t o u t under h i g h t e m p e r a t u r e .  G e n e r a l l y , t h i s form i s  6 e x c l u d e d from t h e d e f i n i t i o n o f m o i s t u r e  content.  P h y s i c o - c h e m i c a l l y bonded w a t e r r e f e r s t o a m o n o m o l e c u l a r s u r f a c e adsorption layer.  Macro- and m i c r o s t r u c t u r e s o f t h e wood s u r f a c e o r t h e  g e o m e t r i c c o n f i g u r a t i o n o f t h e space w a t e r m o l e c u l e s may occupy have a p r o f o u n d e f f e c t on t h e s t r e n g t h and q u a n t i t i e s o f bonds.  Langmuir ( 4 6 ) ,  who f i r s t proposed t h e o r e t i c a l e x p l a n a t i o n o f t h i s m o n o m o l e c u l a r a d s o r p t i o n l a y e r , b e l i e v e d t h a t t h e bonding energy i s about t h e same o r d e r as a c o v a l e n t bond.  Oniithe o t h e r hand, Stamm (82) c o n s i d e r e d t h a t t h i s  monomolecular a d s o r b e d w a t e r o r " s u r f a c e bound" w a t e r i s h e l d by hydrogen bonds which have about o n e - f o u r t h o f t h e c o v a l e n t bond e n e r g y .  This  s t r o n g l y h e l d w a t e r i s one o f t h e reasons t h a t oven-dry w e i g h t o f a p i e c e o f wood i s an a r b i t r a r i l y d e t e r m i n e d  weight.  P h y s i c a l l y bonded w a t e r i s c o n s i d e r e d t o be t h e r e s u l t o f t h e imb a l a n c e o f f o r c e e x e r t e d on w a t e r m o l e c u l e s from t h e s u r f a c e o f t h e a d sorbent.  In o t h e r w o r d s , t h i s p o r t i o n o f w a t e r i s h e l d by l o n g  weak l i n k s due t o p o l a r i z a t i o n o r Van d e r Waals f o r c e s ( 4 1 ) .  range  The w a t e r  adsorbed i n t h i s range i s m u l t i - m o l e c u l a r .  Three w i d e l y r e c e i v e d t h e o r i e s  have been proposed f o r t h e m u l t i - m o l e c u l a r  adsorption.  Zsigmondy ( 1 0 2 ) , who proposed t h e c a p i l l a r y c o n d e n s t a t i o n  theory,  a t t r i b u t e d a d s o r p t i o n t o c o n d e n s a t i o n o f w a t e r vapor i n t h e c a p i l l a r y pores.  The p r e s s u r e o f c o n d e n s a t i o n i s p r o p o r t i o n a l t o t h e r a d i u s o f l i q u i d  meniscus i n a c a p i l l a r y , t h e r e f o r e t h e s m a l l e r t h e c a p i l l a r y r a d i i , t h e f a s t e r condensation occurs.  T h i s t h e o r y can n o t a c c o u n t f o r u n i m o l e c u l a r  a d s o r p t i o n , and i s a p p l i c a b l e o n l y t o r e l a t i v e h u m i d i t i e s o f 9 0 % o r more. P o l a r i z a t i o n t h e o r y (10) c o n s i d e r s a d s o r p t i o n as a r e s u l t o f i n d u c e d d i p o l e a t t r a c t i o n s p r o p a g a t e d from t h e a d s o r b e n t s u r f a c e o v e r s e v e r a l l a y e r s . I t was used t o e x p l a i n t h e s o r p t i o n i s o t h e r m q u a n t i t a t i v e l y , b u t i s now  7 o b s o l e t e l a r g e l y because i t f a i l s t o a c c o u n t f o r t h e b i n d i n g e n e r g y between l a y e r s . B r u n a u e r , Emmett and T e l l e r (13) proposed a t h e o r y t o a c c o u n t f o r m u l t i - m o l e c u l a r a d s o r p t i o n based on t h e a s s u m p t i o n t h a t t h e same f o r c e s t h a t produce c o n d e n s a t i o n a r e a l s o c h i e f l y r e s p o n s i b l e f o r t h e b i n d i n g energy o f m u l t i - m o l e c u l a r a d s o r p t i o n and o n l y t h e f i r s t a d s o r b e d l a y e r i s s u r f a c e bound.  The subsequent l a y e r s a r e a d s o r b e d n o t by t h e s u r f a c e  b u t by t h e p r e c e e d i n g l a y e r s . T h i s i s known as t h e BET t h e o r y . Kollmann and Cote (41) c l a s s i f i e d water h e l d w i t h i n wood i n f o u r phases: water o f c o n s t i t u t i o n ; s u r f a c e bound, monomolecular  layer; multi -  m o l e c u l a r l a y e r s o f d e c r e a s i n g o r d e r o f d i p o l e ; and c a p i l l a r y water.  condensed  T r a n s i t i o n between t h e d i f f e r e n t phases i s n o t s h a r p .  Kollmann  (39) f u r t h e r d i v i d e d t h e c a p i l l a r y c o n d e n s a t i o n c u r v e i n t o " a p p a r e n t " c a p i l l a r y c o n d e n s a t i o n i n s u b m i c r o s c o p i c s t r u c t u r e and r e a l c a p i l l a r y condensation i n the microscopic pores.  A t h r e e component f u r m u l a was  proposed t o d e s c r i b e t h e t o t a l range o f r e l a t i v e h u m i d i t y s o r p t i o n i s o therm. 2.1.2  I n t e r a c t i o n between wood m o i s t u r e and e l e c t r i c a l p r o p e r t i e s Dry wood i s an e x c e l l e n t e l e c t r i c a l i n s u l a t o r . The e l e c t r i c a l c o n -  d u c t i v i t y i s a l m o s t e n t i r e l y due t o a d s o r b e d m o i s t u r e ( 8 2 ) . R e s i s t i v i t y 17  o f oven-dry wood has been o b t a i n e d by e x t r a p o l a t i o n a s 3 x 10 ohm-centimeter  18  t o 3 x 10  ( 1 6 , 8 2 ) . The r e s i s t i v i t y i s i n v e r s e l y p r o p o r t i o n a l t o  moisture content.  From oven-dry t o about 7% m o i s t u r e c o n t e n t , t h e r e i s  a l i n e a r r e l a t i o n s h i p between t h e l o g a r i t h m o f r e s i s t i v i t y and m o i s t u r e c o n t e n t (16,38,70).  Stamm ( 8 2 ) , e s t i m a t e d t h e change i n r e s i s t i v i t y i n t h i s  range as a b o u t 1 0 0 , 0 0 0 - f o l d .  From 7% t o f i b e r s a t u r a t i o n ( 2 8 % ) , t h e l o g a r i -  thm o f r e s i s t i v i t y r e l a t e s l i n e a r l y t o m o i s t u r e c o n t e n t w i t h a d i f f e r e n t s l o p e (38,82).  Above t h e f i b e r s a t u r a t i o n p o i n t , t h e change i n r e s i s t i v i t y  ,8 i s r e l a t i v e l y s m a l l (38, 80). The b r e a k i n g o f l i n e a r i t y a t 5 t o 8% m o i s t u r e c o n t e n t was to correspond  t o the t r a n s i t i o n zone from m o n o m o l e c u l a r t o  cular adsorption.  thought  multi-mole-  M o i s t u r e would be a d i s r u p t e d f i l m a t m o i s t u r e  t e n t s below t h i s r a n g e .  con-  T h i s p r o v i d e d some e x p l a n a t i o n as t o the d r a s t i c  change i n r e s i s t i v i t y below and above t h i s t r a n s i t i o n zone ( 8 2 ) . Lehmann (51) s t u d i e d t h e dependence o f the e l e c t r i c a l c o n d u c t i v i t y o f some h y g r o s c o p i c f i b e r s on t h e i r w a t e r c o n t e n t . f i b e r s a t u r a t i o n p o i n t , the m o i s t u r e  He found t h a t below  s o r p t i o n c u r v e s and d.e.  t i v i t y of d i f f e r e n t natural f i b e r s plotted against moisture very s i m i l a r .  conduc-  content  are  In low m o i s t u r e c o n t e n t r a n g e , the water m o l e c u l e s were  h e l d by c h e m i s o r p t i o n  i n amorphous r e g i o n s of the f i b e r s , hence had  e f f e c t on c o n d u c t i v i t y . c a p i l l a r y condensation  F u r t h e r , as w a t e r a d s o r p t i o n p e n e t r a t e d  no  by  i n t o i n t e r m e c e l l a r c r e v i c e s , with i n c r e a s i n g  hydrogen b o n d i n g , the d.e. c o n d u c t i v i t y a l s o  increased.  The c o m p a r a t i v e e l e c t r i c a l c o n d u c t i v i t y o f pure water h e l d i n a porous body compared w i t h c o n d u c t i v i t y o f the same amount b u l k , i . e . , t h e r e l a t i v e c o n d u c t i v i t y may 10.  of water i n  be as h i g h as a f a c t o r o f  T h i s i n d i c a t e s t e n t i m e s h i g h e r c o n d u c t i v i t y f o r s u r f a c e bound  water then b u l k water ( 8 2 , 1 0 0 ) .  This i s a t t r i b u t a b l e to zeta-potential  a t one hand and l e s s a s s o c i a t i o n between a d s o r b e d w a t e r m o l e c u l e s than b u l k w a t e r on t h e o t h e r hand. At a g i v e n t e m p e r a t u r e and f r e q u e n c y , w i t h m o i s t u r e c o n t e n t (12,27,78).  the d i e l e c t r i c c o n s t a n t  increases  The i n c r e a s e i s a t t r i b u t e d t o t h e h i g h  d i e l e c t r i c c o n s t a n t o f w a t e r ( c a . 80) compared w i t h t h e low d i e l e c t r i c c o n s t a n t o f wood s u b s t a n c e .  Also high moisture content c o n t r i b u t e s to  freedom o f r o t a t i o n f o r t h e c e l l w a l l p o l a r g r o u p s .  T h i s d i e l e c t r i c con-  t a n t o f wood i n c r e a s e s e x p o n e n t i a l l y w i t h m o i s t u r e c o n t e n t below the f i b e r  s a t u r a t i o n p o i n t and i n c r e a s e s l i n e a r l y above t h i s p o i n t ( 7 8 , 8 8 ) . Venkateswaran  and T i w a r i (93) s t u d i e d t h e m o i s t u r e c o n t e n t and d i -  e l e c t r i c p r o p e r t y r e l a t i o n s h i p by e m p l o y i n g a b i n a r y s y s t e m o f w a t e r and wood, and assuming t h a t t h e m a c r o s c o p i c p o l a r i z a t i o n o f t h e s y s t e m f o l l o w s chemical r a t e theory.  F a i r agreement was o b t a i n e d f o r c a l c u l a t e d v a l u e s  and e x p e r i m e n t a l o b s e r v a t i o n s . A d i s r u p t i o n has been o b s e r v e d a t about 6% m o i s t u r e c o n t e n t f o r both d i e l e c t r i c c o n s t a n t and d i e l e c t r i c l o s s t a n g e n t o f wood.  The u n d e r l y i n g  s i g n i f i c a n c e i s c o r r e l a t i o n between t h e Langmuir monomolecular l a y e r and t h e i n f l e c t i o n p o i n t .  adsorption  Trapp and Pungs(84) and Tsutsumi and  Watanabe (86) both have o b s e r v e d t h i s phenomenon/i Kajanne and H o l l m i n g (32) o b s e r v e d a b r u p t change i n d i e l e c t r i c cons t a n t (£') o f wood when m o i s t u r e c o n t e n t was around 4.5%.  They  f o r i t as hydrogen b o n d i n g and by assuming a 4 t o 5% hydrogen  accounted bonding  rate., The b o n d i n g energy was shown t o be 3 t o 4 k c a l p e r mole t h r o u g h v  c a l o r i m e t r i c measurement. Tsiiges and Wada (85) e x p l a i n e d t h i s i n f l e c t i o n o f d i e l e c t r i c d i s p e r s i o n o f p a p e r and c e l l o p h a n e a t 3 and 6% m o i s t u r e c o n t e n t , r e s p e c t i v e l y , as a r e s u l t o f r o t a t i o n a l segmental motions c a u s e d by s o r b e d w a t e r molec u l e s b r e a k i n g t h e i n t e r - a n d i n t r a m o l e c u l a r hydrogen  bonds.  N o r i m o t o and Yamada (62) s t u d i e d d i e l e c t r i c p r o p e r t i e s o f wood i n r e l a t i o n t o wood m o i s t u r e c o n t e n t i n t h e microwave range ( c a . 10 GHz, o r 1 x 1 0 ^ H z ) . They found t h a t t h e wood d i e l e c t r i c c o n s t a n t and l o s s f a c t o r i n r a d i a l d i r e c t i o n i n c r e a s e d s l i g h t l y up t o 5% m o i s t u r e c o n t e n t , then i n c r e a s e d r a p i d l y w i t h i n c r e a s i n g m o i s t u r e c o n t e n t .  They a l s o d i v i d e d  m o i s t u r e a c c o r d i n g t o i t s i n t e r a c t i o n w i t h wood as s u r f a c e bound, m u l t i m o l e c u l a r and c a p i l l a r y condensed w a t e r and a n a l y z e d t h e s e a c c o r d i n g l y . T h e i r r e s u l t s i n d i c a t e d a c l e a r dependence  o f e l e c t r i c a l p r o p e r t i e s on o t h e r  10 physical parameters.  T h e v a l u e s o b t a i n e d f o r s u r f a c e bound, m u l t i -  m o T e c u l a r and c a p i l l a r y condensed w a t e r as r e g a r d s p e c i f i c g r a v i t y , d i e l e c t r i c c o n s t a n t , l o s s f a c t o r and s p e c i f i c p o l a r i z a t i o n were g i v e n . D i e l e c t r i c c o n s t a n t s were shown t o change from 7.1 t o 63.5, l o s s f a c t o r from 1.6 t o 6.5 and s p e c i f i c p o l a r i z a t i o n from 1.1 t o 14.0 f o r s u r f a c e bound and c a p i l l a r y condensed w a t e r , r e s p e c t i v e l y . 2.2 E f f e c t o f Wood V a r i a b i l i t y on E l e c t r i c a l P r o p e r t i e s . The c o m p l e x i t y difficult.  o f wood s t r u c t u r e makes t h e s t u d y o f i t s p r o p e r t i e s  Nevertheless,  t h e i n t e r d e p e n d e n c e o f c e r t a i n wood p r o p e r t i e s  and wood components such as d e n s i t y , f i b e r l e n g t h , g r a i n a n g l e and chemica.l 'composition  i s well recognized.  Due t o t h e c o m p l e x i t y  o f each i n d i -  v i d u a l p r o p e r t y , i n t e r a c t i o n s between them a r e o f t e n s u b t l e and i l l - d e f i n e d . In many c a s e , only/phenomenal o r q u a l i t a t i v e i n t e r d e p e n d e n c e Can be observed ( 2 3 ) . L i t t l e work has been done r e l a t i n g wood e l e c t r i c a l r p r o p e r t i e s t o o t h e r wood p h y s i c a l , chemical  or morphological  properties.  Practically  no l i t e r a t u r e i s a v a i l a b l e d e a l i n g w i t h wood e l e c t r i c a l p r o p e r t i e s i n terms o f wood zones and t r e e h e i g h t l e v e l s . O n l y i n d i r e c t i n f e r e n c e s may be drawn on e l e c t r i c a l b e h a v i o u r from a t r e e .  i n r e g a r d t o t h e p o s i t i o n o f wood sampled  H e r e , p r o v i s i o n s have t o be made f o r c o n s i d e r a b l e  specula-  t i o n , s i n c e most o f t h e s e s t u d i e s were done on d i s i n t e g r a t e d wood o r wood components, such as p u l p s and e l e c t r i c a l c o n d e n s e r  papers.  Some between t r e e and between s p e c i e s d i f f e r e n c e s on e l e c t r i c a l p r o p e r t i e s o f wood have been s t u d i e d , b u t t h e s e were n o t d i r e c t e d t o t h e present s p e c i f i c i n t e r e s t .  In f a c t , knowledge a t t h i s l e v e l a r i s e s as  b y - p r o d u c t o f s t u d i e s on o t h e r a f f i l a t e d s u b j e c t s . In t h e f o l l o w i n g r e v i e w , wood c h a r a c t e r i s t i c s which a r e r e p o r t e d t o  11 a f f e c t wood e l e c t r i c a l b e h a v i o u r a r e d i s c u s s e d . 2.2.1  Wood p h y s i c a l p r o p e r t i e s i n r e l a t i o n t o e l e c t r i c a l  properties  A most p r o m i n e n t s u b j e c t i n wood p h y s i c a l p r o p e r t i e s i s s p e c i f i c g r a v i t y , w h i c h i s t h e r a t i o o f wood o v e n - d r y w e i g h t and t h e w e i g h t o f an equal volume o f d i s p l a c e d w a t e r .  Wood d e n s i t y i s d e f i n e d as w e i g h t p e r  u n i t volume. There i s no f i n a l agreement on t h e e f f e c t o f s p e c i f i c g r a v i t y on wood d i r e c t c u r r e n t c o n d u c t i v i t y .  Y a v o r s k y (99) and Stamm (82) both  c o n s i d e r e d t h a t wood c o n d u c t i v i t y s h o u l d show a p o s i t i v e c o r r e l a t i o n w i t h specific gravity.  H a r t (25) t h e o r i z e d t h e e f f e c t o f g r o s s anatomy upon  c o n d u c t i v i t y o f wood w i t h t h e same u n d e r l y i n g a s s u m p t i o n o f a p o s i t i v e specific gravity-conductivity correlation.  However, l i t t l e  e v i d e n c e has been g i v e n i n s u p p o r t o f t h i s view.  experimental  Data f r o m t h e Wood  Handbook (2) and a r e c e n t s t u d y by Venkateswaran (91) i n d i c a t e t h a t d i f f e r e n c e s due t o s p e c i e s e f f e c t s a r e much s t r o n g e r than t h e s p e c i f i c g r a v i t y effect. A l s o , b e c a u s e o f t h e l o g a r i t h m r e l a t i o n s h i p between m o i s t u r e  content  and d i r e c t c u r r e n t c o n d u c t i v i t y o f wood, d i f f e r e n c e s i n s p e c i f i c g r a v i t y have a m i n o r e f f e c t upon c o n d u c t i v i t y , e . g . , a two f o l d d i f f e r e n c e i n s p e c i f i c g r a v i t y may r e s u l t i n a 1 t o 2% m e t e r r e a d i n g d i f f e r e n c e f o r moisture content (82). The e f f e c t o f wood d e n s i t y on i t s d i e l e c t r i c p r o p e r t i e s has been w e l l recognized.  Peterson  (70) s t u d i e d t h e r e l a t i o n s h i p f o r D o u g l a s - f i r  (Pseudotsuga menziesii) (Mirb.)Franco) lationship.  wood a n d f o u n d a c u r v e l i n e a r r e -  When m o i s t u r e c o n t e n t i s above 6%,  there i s a l i n e a r r e -  l a t i o n s h i p between d i e l e c t r i c c o n s t a n t (£') and d e n s i t y (P)  (f-8 ^63^78).  12 D e l e v a n t i and Hansen (18) found t h a t t h e 5' o f k r a f t paper was r e l a t e d t o d e n s i t y p by t h e C l a u s i u s - M o s o t t i  U'-  relation:  1 ) / U ' + 2) « p  [1]  Skaar (78) d i s c o v e r e d a c o r r e l a t i o n between d e n s i t y and t h e t r a n s verse loss tangent o f oven-dried  wood.  Peterson  (70) s u p p o r t e d t h e s e  f i n d i n g s t h a t a p o s i t i v e c o r r e l a t i o n e x i s t s between t h e d i e l e c t r i c l o s s and d e n s i t y o f wood.  However, he n o t e d t h a t t h e e f f e c t i s not so marked  as between d i e l e c t r i c c o n s t a n t and d e n s i t y .  D e l e v a n t i and Hansen (18)  a l s o noted a l i n e a r r e l a t i o n s h i p between t h e l o s s f a c t o r and d e n s i t y . N o r i m o t o and Yamada (63) f o u n d a s i m i l a r l i n e a r r e l a t i o n s h i p between l o s s f a c t o r i n l o n g i t u d i n a l d i r e c t i o n ( £ " ) , l o s s f a c t o r o f wood s u b s t a n c e U,")  and s p e c i f i c g r a v i t y (p ) , and gave t h e e q u a t i o n a s :  p  However, t h e f u n c t i o n was found t o be a f f e c t e d by t e m p e r a t u r e and frequency. Hearmon and Burcham ( 2 9 ) , on t h e o t h e r hand, have d e c i d e d t h a t t h e r e l a t i o n s h i p between l o s s t a n g e n t and d e n s i t y f o r a i r - d r i e d wood was ambiguous.  L i n (54) i n a r e c e n t work, i n w h i c h he assumed wood t o be an  o r t h o g r o p i c d i e l e c t r i c m a t e r i a l and c a l c u l a t e d t h e r e s u l t s by s t e p w i s e r e g r e s s i o n a n a l y s i s , a l s o f o u n d t h a t m o i s t u r e c o n t e n t c o n t r i b u t e d 94% o f t h e v a r i a b i l i t y i n d i e l e c t r i c c o n s t a n t and 84% f o r a . c . r e s i s t i v i t y and loss tangent.  Incorporation  o f d e n s i t y a s an a d d i t i o n a l i n d e p e n d e n t v a r i -  a b l e improved t h e r e g r e s s i o n v e r y l i t t l e .  S p e c i f i c g r a v i t y had v i r t u a l l y  no e f f e c t on t h e r e g r e s s i o n model. I t i s l i k e l y t h a t t h e e f f e c t o f d e n s i t y o r s p e c i f i c g r a v i t y on d i e l e c t r i c p r o p e r t i e s o f wood i s p o s i t i v e o n l y a t o v e n - d r y c o n d i t i o n .  At  o t h e r m o i s t u r e c o n t e n t s , t h e e f f e c t i s l a r g e l y masked by t h e predominance  13 o f m o i s t u r e and t h e r e b y d i f f i c u l t t o a s s e s s . 2.2.2 Wood a n a t o m i c a l p r o p e r t i e s i n r e l a t i o n t o e l e c t r i c a l p r o p e r t i e s M o r p h o l o g i c a l p r o p e r t i e s have a t t r a c t e d t h e l e a s t a t t e n t i o n i n t h i s r e g a r d , and f r e q u e n t l y s t u d i e s were done on s e p a r a t e d f i b e r , r a t h e r than on wood i t s e l f . Some s t u d i e s on f i b e r l e n g t h i n r e l a t i o n t o e l e c t r i c a l p r o p e r t i e s have been done i n c o n n e c t i o n w i t h condenser  papers.  C a l l i n a n (14) s t u d i e d t h e e l e c t r i c a l p r o p e r t i e s o f handsheets from u n b l e a c h e d  k r a f t , semibleached  k r a f t and m e c h a n i c a l  made  p u l p and found  t h a t d i e l e c t r i c constant and l o s s f a c t o r v a r i e d n o t o n l y with chemical c o m p o s i t i o n o f t h e p u l p s , b u t a l s o were c o r r e l a t e d t o f i b e r l e n g t h .  The  e x p l a n a t i o n was t h a t l o n g e r f i b e r s c o n t a i n e d l e s s e x t r a c t i v e s and a s h than short f i b e r s .  I n o t h e r s i m i l a r s t u d i e s ( 1 0 1 ) , t h e same c o n c l u s i o n  was r e a c h e d b u t w i t h e x p l a n a t i o n t h a t s h o r t f i b e r s a r e more l i k e l y t o form  1  a c o n t i n u o u s m o n o m o l e c u l a r a d s o r p t i o n l a y e r under low m o i s t u r e  content.  Long f i b e r s would have d i s c o n t i n u e d w a t e r f i l m , s e p a r a t e d by  a i r b u b b l e s , t h u s c o n t r i b u t i n g t o p o o r e r p o l a r i z a t i o n and lower v a l u e s o f £' and £ " i n l o n g f i b e r s . G a l l a y (23) p o i n t e d o u t t h e importance i n g v a r i o u s paper p r o p e r t i e s .  of f i b e r length i n c o r r e l a t -  T h i s a p p e a r s t o be a c r i t i c a l p a r a m e t e r  in various physical properties. Due t o t h e e l o n g a t e d shape o f most wood e l e m e n t s , t h e i r a l i g n m e n t a c c o r d i n g t o t h e t r e e l o n g i t u d i n a l a x i s and t h e near o r t h o t r o p i c a l i g n ment o f m i c r o f i b r i l a n g l e , t h e r e i s a n i s o t r o p y o f wood p r o p e r t i e s p a r a l l e l and p e r p e n d i c u l a r t o t h e g r a i n d i r e c t i o n .  14  H a r t (25) t h e o r i z e d on e f f e c t s o f g r o s s wood anatomy on c o n d u c t i v i t y and showed t h a t by assuming an a n i s o t r o p i c c e l l w a l l s u b s t a n c e ,  the trans-  v e r s e c o n d u c t i v i t y o f wood specimens w o u l d be o n l y o n e - h a l f o f t h e l o n g itudinal conductivity.  T h i s a r i s e s s i m p l y as a r e s u l t o f t h e gross  cell-  u l a r s t r u c t u r e o f wood. I t has been w e l l e s t a b l i s h e d t h a t t h e d i r e c t c u r r e n t r e s i s t i v i t y o f wood a c r o s s t h e g r a i n i s about 2.3 t o 4.5 times h i g h e r than a l o n g t h e grain.  F o r some pored wood s p e c i e s , t h e r a t i o may reach 8 t i m e s ( 3 8 ,  72, 8 2 ) . These d i f f e r e n c e s a r e r e f l e c t i o n s o f s t r u c t u r a l v a r i a t i o n s , and are independent o f moisture content (53, 8 2 ) . In p e r p e n d i c u l a r t o g r a i n d i r e c t i o n , t h e r e i s a 10 t o 12% c o n d u c t i v i t y r e d u c t i o n i n t a n g e n t i a l d i r e c t i o n as compared w i t h r a d i a l d i r e c t i o n . This i s a t t r i b u t e d to c e l l u l a r misalignment i n tangential d i r e c t i o n o f c o n i f e r s , and t h e p r e s e n c e o f rays ( 2 5 ) . The same phenomena a l s o p r e v a i l i n d i e l e c t r i c p r o p e r t i e s .  Dielectric  c o n s t a n t o f wood a l o n g t h e g r a i n d i r e c t i o n i s always h i g h e r than i n the t r a n s v e r s e d i r e c t i o n .  S k a a r (78) c o n s i d e r e d t h e d i f f e r e n c e a t t r i b u t a b l e  to m o l e c u l a r s t r u c t u r e o f t h e c e l l w a l l .  Orientation o f the c e l l u l o s e  c h a i n s i s l a r g e l y o r t h o t r o p i c , w i t h t h e h y d r o x y l groups o f c e l l u l o s e h a v i n g more f r e e d o m a l o n g t h e g r a i n than a c r o s s t h e g r a i n . L i n (54) f o u n d t h a t wood behaved as an o r t h o t r o p i c d i e l e c t r i c m a t e r i a l w i t h o u t s e r i o u s d e v i a t i o n when t h e m o i s t u r e  c o n t e n t was below 15%. Above  15% m o i s t u r e c o n t e n t , t h e d e v i a t i o n o f t h e o r e t i c a l l y c a l c u l a t e d v a l u e s f r o m experimental,  v a l u e s became s i g n i f i c a n t i n t h e l o n g i t u d i n a l - r a d i a l p l a n e , t h e  maximum then c o i n c i d e d t o m i c r o f i b r i l a n g l e . An a n i s o t r o p y o f d i e l e c t r i c p r o p e r t i e s i s a l s o p r e s e n t between r a d i a l and t a n g e n t i a l d i r e c t i o n s .  The o r i g i n o f t h e s e v a r i a t i o n s were c o n s i d e r e d  15 by Uyemura (88) and Krciner and Pungs (35) as r e s u l t i n g f r o m c e l l w a l l o r i e n t a t i o n , r a t h e r than from m i c r o s t r u c t u r a l d i f f e r e n c e s . made s i m i l a r o b s e r v a t i o n s .  Nanassy  (60)  R a f a l s k i (74) d e m o n s t r a t e d t h a t by c o m p r e s s i n g  beech wood specimens a l o n g both r a d i a l and t a n g e n t i a l d i r e c t i o n s , the dielectn"ci,property  d i f f e r n c e s between t h e two d i r e c t i o n s  gradually  r e d u c e d , f i n a l l y r e a c h i n g the same v a l u e as the s p e c i f i c g r a v i t y o f the specimens became  1.45.  McLauchlen et_ a]_. (55) r e c e n t l y p a t e n t e d  a grain slope i n d i c a t o r  based on t h i s a n i s o t r o p i c d i e l e c t r i c p r o p e r t y .  However, as p o i n t e d  out  by L i n ( 5 4 ) , a t high m o i s t u r e c o n t e n t m i c r o f i b r i l o r i e n t a t i o n has a s i g n i f i c a n t e f f e c t on wood d i e l e c t r i c b e h a v i o u r . ^ F u r t h e r s t u d i e s were u r g e d . F a i n b e r g et_ al_. (21) d i s c u s s e d e l e c t r i c a l a n i s o t r o p y o f c e l l u l o s e materials, e s p e c i a l l y regenerated  celluloses.  D i f f i c u l t i e s in  determining  d i e l e c t r i c v . a n i s o t r o p y were t h o u g h t due t o the p r e s e n c e of w a t e r and porous n a t u r e o f t h e h y d r o p h i l i c f i b e r s .  the  Calculated anisotropy values  for  non-drawn v i s c o s e rayon c o r d f i b e r and h i g h - t e n a c i t y rayon c o r d f i b e r v a r i e d f r o m 5.23 0.0202 t o 0.0395.  t o 6.15,  as compared w i t h o p t i c a l b i r e f r i n g e n c e v a l u e s  of  C o r r e l a t i o n s between the o r i e n t a t i o n , d i e l e c t r i c p e r m i t -  t i v i t y and o p t i c a l b i r e f r i n g e n c e were s u g g e s t e d N o r i m o t o and Yamada (64) found a f r e q u e n c y dependency i n d i e l e c t r i c anisotropy.  At h i g h f r e q u e n c y no d i f f e r e n c e was o b s e r v e d between p a r a l l e l  and p e r p e n d i c u l a r  to grain d i r e c t i o n s .  T h i s was i n t e r p r e t e d as i n d i c a t i n g  t h a t d i e l e c t r i c a n i s o t r p y i s c a u s e d m a i n l y by m a c r o s c o p i c s t r u c t u r a l d i f ferences.  At low f r e q u e n c y , a l a r g e a n i s o t r o p y d i f f e r e n c e was  which c o r r e s p o n d e d t o p o l a r i z a t i o n o f h y d r o x y l  observed,  groups i n t h e d i s o r i e n t e d  r e g i o n s o f c e l l u l o s e c h a i n s . T h i s i n d i c a t e d a dependence o f d i e l e c t r i c ~  16 a n i s o t r o p y on m i c r o s t n u c t u r e and movement o f m o l e c u l e s i n wood. 2.2.3.  Wood c h e m i c a l c o m p o s i t i o n i n r e l a t i o n t o e l e c t r i c a l p r o p e r t i e s  A b r i e f r e v i e w o f t h e wood d i r e c t c u r r e n t c o n d u c t i o n mechanism i s w a r r a n t e d here i n o r d e r t o comprehend s i g n i f i c a n c e o f c h e m i c a l t i o n on wood e l e c t r i c a l  composi-  conduction.  The mechanism o f d.e. c o n d u c t i o n i n wood i s t h o u g h t t o be i o n i c r a t h e r than e l e c t r o n i c ( 3 , 12, 27, 5 2 ) . The m i g r a t i o n o f i o n s i n wood, under an e l e c t r i c a l f i e l d has been demonstrated  by v a r i o u s e x p e r i m e n t a l  e v i d e n c e , such as t h e use o f . r a d i o a c t i v e i s o t o p e s ( 5 2 ) , c o l o r r e a c t i o n s o f m e t a l l i c i o n s ( 5 8 ) , pH v a l u e change near t h e e l e c t r o d e s (30) and neutron a c t i v a t i o n analysis (47). I t o (30) b e l i e v e d t h a t i n a d d i t o i n t o t h e u s u a l i o n i c c o n d u c t i o n , t h e e l e c t r o k i n e t i c phenomenon ( z e t a - p o t e n t i a l ) p l a y e d an i m p o r t a n t r o l e , s i n c e the wood specimen i s e q u i v a l e n t t o a b i n a r y system composed o f membrane and water.  Yurev and P o z i n (100) demonstrated  t h e importance o f s u r f a c e conduc-  t i v i t y a s s o c i a t e d w i t h z e t a - p o t e n t i a l , which i s s u b s t a n t i a l l y h i g h e r than water c o n d u c t i v i t y o f t h e same volume. Murphy (59) a p p l i e d t h e t h e o r y o f e l e c t r i c a l c o n d u c t i o n i n i o n i c c r y s t a l s t o c e l l u l o s e and p r o p o s e d t h a t c e l l u l o s e c o n d u c t i v i t y i s t h e sum o f i n t r i s i c and e x t r i n s i c c o n d u c t i o n . of c e l l u l o s e .  The f o r m e r a^e t h e i o n i z e d p a r t  These i o n s a r e e i t h e r bounded on t h e s u r f a c e o f c e l l u l o s e  m i c e l l e s o r e x i s t ascifree i o n s .  L i n (52) proposed a model f o r i o n i c  c o n d u c t i o n i n wood and p o i n t e d o u t t h a t t h e number o f charge c a r r i e r s i n wood i s t h e major f a c t o r i n d e t e r m i n i n g c o n d u c t i o n mechanism a c r o s s t h e m o i s t u r e range from oven-dry c o n d i t i o n t o 20% m o i s t u r e .  At higher moisture  contents,'.the degree o f d i s s o c i a t i o n o f adsorbed i o n s and t h e m o b i l i t y o f t h e s e i o n s become d e t e r m i n i n g f a c t o r s .  17 The p r e s e n c e o f water s o l u b l e e l e c t r o l y t e s i n w o o c L i s , t h e r e f o r e , v e r y i m p o r t a n t t o d.e. c o n d u c t i v i t y . One l i k e l y s o u r c e o f t h e s e i o n s i s the ash c o n t e n t o f wood. Ash i s u s u a l l y low i n most woods, and a good p o r t i o n o f i t i s i n water i n s o l u b l e forms (38, 8 1 ) .  Consequently, i t  may have o n l y m i n o r e f f e c t on t h e e l e c t r i c a l p r o p e r t i e s . C e l l u l o s e c h a i n s a r e t h o u g h t t o c o n t a i n some h i g h l y p o l a r groups which a r e a v a i l a b l e as i o n exchange s i t e s .  M e t a l l i c i o n s a d s o r b e d on t h e s e s i t e s a r e h e l d by  s t r o n g bonds w i t h b o n d i n g e n e r g y a p p r o x i m a t e l y t h e same as c o v a l e n t bondsx(12, 1 7 ) .  Under t h e i n f l u e n c e o f m o i s t u r e , a c t i v a t i o n energy i s  r e d u c e d s u b s t a n t i a l l y and w a t e r i t s e l f i s added t o m e t a l l i c i o n s t o form c h a r g e c a r r i e r s (28, 5 2 ) . Weatherwax and Stamm (98) found t h a t d e p o s i t i o n o f n o n h y g r o s c o p i c , low c o n d u c t i v i t y m a t e r i a l s , such as p h e n o l i c r e s i n s , i n wood r e d u c e d d.e. c o n d u c t i v i t y because t h e s e s u b s t a n c e s r e d u c e d wood h y g r o s c o p i c i t y . As a l o n g c h a i n p o l y e r composed o f numerous h y d r o x y l g r o u p s , a l s o o f v a r i a b l e p a c k i n g d e n s i t y , c e l l u l o s e has been t h e s u b j e c t o f d i e l e c t r i c s t u d i e s f o r some t i m e , e s p e c i a l l y due t o i t s i m p o r t a n c e as i n s u l a t i o n paper i n e l e c t r i c c a p a c i t o r . B o l o t o v a and Sharkov (8) and V e r s e p u t (95) both found t h a t t h e d i e l e c t r i c constant ( £' ) of c e l l u l o s i c m a t e r i a l s decreased with i n c r e a s i n g crystal 1inity.  Kane (33) employed a b i n a r y system and f o u n d a good  r e g r e s s i o n between v a p o r a c c e s s i b i l i t y o f c e l l u l o s e and £' , w i t h s m a l l d e v i a t i o n from the l e a s t square  regression line.  The £' o f a c c e s s i b l e  c e l l u l o s e was about 9, t h a t o f i n a c c e s s i b l e c e l l u l o s e 4.  The r e a s o n f o r  a h i g h d i e l e c t r i c c o n s t a n t and l o s s f a c t o r o f amorphous c e l l u l o s e i s t h o u g h t t o r e s u l t from g r e a t e r m o b i l i t y o r p o l a r i z a b i l i t y o f h y d r o x y l groups i n t h e s e r e g i o n s , whereas h y d r o x y l groups i n c r y s t a l l i n e r e g i o n s a r e hydrogen bonded and r e q u i r e e x | r a e n e r g y f o r p o l a r i z a t i o n .  18 Pande (68) d e s c r i b e d a t h e o r e t i c a l approach  f o r evaluating cellulose  c r y s t a l l i n i t y through d i e l e c t r i c c o n s t a n t measurement.  G l a d s t o n e and  Dale's law f o r r e f r a c t i v e index and d e n s i t y o f a s u b s t a n c e was used t o d e r i v e an e q u a t i o n r e l a t i n g average d i e l e c t r i c c o n s t a n t w i t h volume fraction of cellulose crystallinity. poi>nte'dout t h a t t h e G l a d s t o n e - D a l e  However, Venkateswaran (89) l a t e r  law i s i n d e p e n d e n t  of c e l l u l o s e cry-  s t a l l i n e c o n t e n t , thus i t i s i n v a l i d ; ! t o c a l c u l a t e c e l l u l o s e c r y s t a l l i n i t y v i a d i e l e c t r i c measurement. N o r i m o t o and Yamada (65) compared t h e d i e l e c t r i c c o n s t a n t and l o s s t a n g e n t o f n i n e d r y c e l l u l o s e p r e p a r a t i o n s and t h e i r c o r r e s p o n d i n g c r y s t a l l i n i t y degrees as d e t e r m i n e d from m o i s t u r e r e g a i n and x - r a y d i f f r a c t i o n . They were a b l e t o d e r i v e and e x p e r i m e n t a l l y v e r i f y a r e l a t i o n s h i p between d i e l e c t r i c p r o p e r t i e s and c e l l u l o s e amorphous c o n t e n t . The e f f e c t o f l i g n i n c o n t e n t on d i e l e c t r i c l o s s f a c t o r has been a s u b j e c t o f i n t e r e s t i n i n s u l a t i n g paper r e s e a r c h . B o r o d u l i n a e t al_. (9) and D e l e v a n t i and Hansen (18) p o i n t e d p u t t h e d e t r i m e n t a l e f f e c t o f l i g n i n i n c o n t r i b u t i n g t o l o s s f a c t o r . NeJbVasov e t al_. (61) s t u d i e d d i e l e c t r i c c o n s t a n t o f l i g n i n s o l u t i o n s i n d i o x a n e by assuming a 1 i g n i n - d i o x a n e - w a t e r  t e r n a r y system.  The r e s u l t s f o l l o w e d  the C l a u s i u s - M o s o t t i r e l a t i o n ( E q . l ) . The p o l a r i z a b i l i t y o f l i g n i n molec u l e s , as c a l c u l a t e d from t h e e x p e r i m e n t a l d a t a , was h i g h e r by a f a c t o r o f 1000 than t h a t o f w a t e r . More r e c e n t l y , Venkateswaran (92) found a l i n e a r r e l a t i o n s h i p between p e r c e n t a g e l i g n i n and d i e l e c t r i c p e r m i t t i v i t y ( d i e l e c t r i c c o n s t a n t £ ' ) . Woods w i t h l i g n i n c o n t e n t s r a n g i n g from 15 t o 35% were s t u d i e d .  The h i g h e r  the k l a s o n l i g n i n c o n t e n t , t h e lower t h e s p e c i f i c p e r m i t t i v i t y as measured perpendicular to the grain.  No e x p l a n a t i o n was g i v e n f o r t h i s phenomenom,  19 b u t a s u g g e s t i o n was made t o develop t h i s r e l a t i o n s h i p i n t o a nond e s t r u c t i v e means f o r l i g n i n measurement. Venkateswaran (90) has found l i t t l e a s s o c i a t i o n between the  hem-  i c e l l u l o s e f r a c t i o n and wood p e r m i t t i v i t y . B o r o d u l i n a e t al_. (9) f o u n d t h a t the p e n t o s a n c o n t e n t o f k r a f t pulp had an i n h i b i t o r y e f f e c t on sodium i o n s as t o r e d u c e d i e l e c t r i c l o s s e s .  I f pentosan c o n t e n t was l o w e r than  5 t o 6% the p r e s e n c e o f sodium i o n s i n c r e a s e d d i e l e c t r i c l o s s s u b s t a n t i a l l y , e s p e c i a l l y at high temperature. H e m i c e l 1 u l o s e has been t r e a t e d as a r e l a t i v e l y s h o r t c h a i n e d amorphous compound, w i t h some b r a n c h i n g and c o n t a i n i n g p o l a r g r o u p s , l i k e h y r o x y l , a c e t y l and c a r b o x y l . laxation behaviour  T h e s e f e a t u r e s may c o n t r i b u t e to the d i e l e c t r i c r e -  as s u c h .  L a z a r e v (49) i n a s t u d y o f r o s i n used f o r i n s u l a t i n g p u r p o s e s , f o u n d t h a t a b e i t i c a c i d c o n t r i b u t e d s i g n i f i c a n t l y to l o w e r d i e l e c t r i c l o s s e s , whereas the r o s i n v o l a t i l . e s were d e t r i m e n t a l t o i n s u l a t i n g q u a l i t i e s . Vermaas(94) s t u d i e d the d i e l e c t r i c p r o p e r t i e s o f c l u s t e r p i n e pinaster;Fran.)  as a f u n c t i o n o f i t s a l c o h o l - b e n z e n e  (Pinus  soluble content.  No  s i g n i f i c a n t i n f l u e n c e on d i e l e c t r i c c o n s t a n t was f o u n d f o r wood e x t r a c t i v e s . The i n f l u e n c e o f e x t r a c t i v e s on the l o s s t a n g e n t depended upon the g r a i n d i r e c t i o n , where l o s s t a n g e n t a l o n g the g r a i n was not i n f l u e n c e d , w h i l e i n the r a d i a l d i r e c t i o n i t i n c r e a s e d and i n the t a n g e n t i a l d i r e c t i o n i t decreased with increasing e x t r a c t i v e content.  Norimoto and Yamada (63)  f o u n d l i t t l e d i f f e r e n c e between d i e l e c t r i c l o s s f a c t o r ( £")of u n t r e a t e d i  r  e x t r a c t e d wood samples. exception.  and  .•  Kusunoki (Cinnamomum camphora S i e b . ) was the o n l y  T h i s was t h o u g h t t o be due t o the p r e s e n c e o f c o n d u c t i v e  p u r i t i e s l i k e camphor, w h i c h were removed by e x t r a c t i o n .  im-  Uyemura (88)  a l s o found l i t t l e i n f l u e n c e o f o r g a n i c e x t r a c t i v e s on d i e l e c t r i c p r o p e r t i e s .  20 M i n e r a l c o n t e n t i n wood, a c c o r d i n g t o S k a a r (78) does not a f f e c t t o any s i g n i f i c a n t e x t e n t the d i e l e c t r i c c o n s t a n t a t r a d i o  frequency,  but has i n f l u e n c e on the power l o s s and l o s s t a n g e n t w h i c h a r e a f u n c t i o n o f a.c. c o n d u c t i v i t y ,  V e n k a t e s w a r a n (92) suggested  that i n dry  wood, ash c o n t e n t does not seem t o have any e f f e c t on d i e l e c t r i c p e r m i t t i v i t y and d.e. c o n d u c t i v i t y , due t o t h e random d i s t r i b u t i o n o f m e t a l l i c e l e m e n t s i n wood. On the o t h e r hand, r e s e a r c h e r s on i n s u l a t i n g p a p e r s a l w a y s s t r e s s importance of these i m p u r i t i e s to d i e l e c t r i c l o s s e s .  Delevanti  and  Hansen (18) showed t h a t a c i d e x t r a c t i o n , s a l t c o n t e n t and e s p e c i a l l y m e t a l l i c ions c o n t r i b u t e d a l a r g e p o r t i o n of the l o s s f a c t o r .  Among  the m e t a l l i c i o n s , b i v a l e n t i o n s l i k e c a l c i u m and magnesium have l e s s i n f l u e n c e on paper d i e l e c t r i c p r o p e r t i e s than m o n o v a l e n t i o n s l i k e sodium and p o t a s s i u m ( 6 ) . The above r e v i e w , h o p e f u l l y , p r o v i d e s a background f o r u n d e r standing r e s u l t s of the present  study.  21  3,0 3.1  MATERIALS AND METHODS  Sample C o l l e c t i o n Through arrangements  made by CLMA and t h e e f f o r t s o f Mr, M, Noel  o f t h e M e r r i l l and Wagner Lumber Co., W i l l i a m s Lake, B. C , t h e were c o l l e c t e d from t h e company woodyard on June 4 t h , 1974. ed w h o l e - t r e e l e n g t h s were s e l e c t e d . For w i t h i n s p e c i e s  samples  Fresh f e l l -  comparisons,  f o u r stems and one c o m p r e s s i o n wood stump o f l o d g e p o l e p i n e ; ( P i n u s c o n t o r t a v a r . l a t i f o l i a Engelm.) were c h o s e n .  One stem each o f w h i t e  s p r u c e ( P i c e a g l a u c a (Moench.) V o s s . ) , D o u g l a s - f i r ( P s e u d o t s u g a m e n z i e s i i var. g l a u c a ( B e i s s n . ) F r a n c o ) and s u b a l p i n e f i r ( A b i e s l a s i o c a r p a (Hook.) N u t t l . ) were a l s o chosen f o r between s p e c i e s c o m p a r i s o n s . s p e c i e s a r e i m p o r t a n t t o t h e B r i t i s h Columbia A s y s t e m a t i c sampling scheme was used. at f i v e height levels. each h e i g h t l e v e l - . the stem.  I n t e r i o r lumber i n d u s t r y . Each t r e e stem was  sampled  I n t e r n o d a l segments o f c a . 45 cm were c u t from  Two segments were c u t from t h e l i v i n g crown p a r t o f  D i s t a n c e s between t h e segments were a d j u s t e d s l i g h t l y t o  a v o i d s e r i o u s d e f e c t s and branch w h o r l s . Appendix  A l l these  I.  Each segment  Data on samples a r e g i v e n i n  was marked and wrapped i n s a r a n f i l m and  s t o r e d i n a p o l y e t h y l e n e bag t o p r e v e n t m o i s t u r e l o s s .  After transport-  i n g samples t o t h e F a c u l t y o f F o r e s t r y , U n i v e r s i t y o f B r i t i s h  Columbia,  t h e y were s t o r e d i n a c o l d r o o m a t 2°C. 3.2  Specimen P r e p a r a t i o n s The wood segments were sawn l o n g i t u d i n a l l y i n t o h a l v e s a c r o s s t h e  centers. slab  Then a l o n g one o f t h e two h a l v e s from e a c h segment a 3 cm t h i c k  was c u t .  Each s l a b was f u r t h e r sawn l o n g i t u d i n a l l y and p a r a l l e l t o  22 t h e t a n g e n t i a l f a c e s i n t o h a l v e s t h r o u g h t h e p i t h t o g i v e two r a d i a l s e r i e s c o u n t e r p a r t s . The sample s l a b s were j o i n t e d on t h e edges and i p l a n e d t o g i v e p a r a l l e l s u r f a c e s . The s l a b s were marked i n t o two t o f i v e 2.5 cm wide s t r i p s as r a d i a l s e r i e s . were s e p a r a t e d .  Sapwood and heartwood  zones  The c e n t r a l growth i n c r e m e n t o f each marked s t r i p was  c o u n t e d from t h e p i t h and r e c o r d e d ( s e e Appendix I I ) . Each s t r i p was f u r t h e r marked and coded i n t o f o u r 10 cm l o n g specimens.  D e f e c t s such  a s k n o t s , p i t c h p o c k e t s and bark p o c k e t s were e x c l u d e d from  specimens  as much as p o s s i b l e . The specimen p i e c e s were t h e n p r e p a r e d by sawing t h e s l a b s i n t o s t r i p s a l o n g t h e marked l i n e s and d i v i d i n g them l o n g i t u d i n a l l y i n t o f o u r 2.5 x 2.5 x 10 cm p i e c e s . These f o u r specimen p i e c e s were c o n s i d e r e d as one g r o u p .  Specimens from t h e same r a d i a l s e r i e s  were p u t i n one p o l y e t h y l e n e bag and kept i n t h e c o l d r o o m .  A schematic  d i a g r a m f o r specimen p r e p a r a t i o n i s p r e s e n t e d as F i g 1. 3.3 M o i s t u r e Measurements 3.3.1 I n s t r u m e n t s and c a l i b r a t i o n Commercial  r e s i s t a n c e and p o w e r - l o s s t y p e m o i s t u r e m e t e r s were used  t o a s s e s s specimen m o i s t u r e c o n t e n t s . The r e s i s t a n c e t y p e m o i s t u r e meter used was a Delmhorst RC-1B model, e q u i p p e d w i t h 26E e l e c t r o d e s o f 1 - i n c h p i n s . The p o w e r - l o s s meter used was a M o i s t u r e R e g i s t e r , Model L ( s e e Appendix I I I f o r t h e meter c i r c u i t r y ) . The r e s i s t a n c e t y p e m o i s t u r e meter was c o r r e c t e d b e f o r e t h e e x p e r i ment w i t h s t a n d a r d r e s i s t a n c e s . Readings on some t e s t p i e c e s were compared w i t h meter r e a d i n g s o f a s i m i l a r model from t h e Western F o r e s t Products Laboratory.  T e s t s showed good  agreement.  The powers-loss t y p e m o i s t u r e meter ( M o i s t u r e R e g i s t e r , Model L) has a b u i l t - i n standard.  B e f o r e each s e r i e s o f measurements t h e meter was  23 s t a n d a r d i z e d and z e r o e d a c c o r d i n g t o i n s t r u c t i o n s .  Necessary a d j u s t -  ments were made by t u n i n g t h e t r i m . 3.3.2 M o i s t u r e c o n d i t i o n i n g and measurement At f i r s t , " g r e e n " specimens were weighed i n d i v i d u a l l y and dimens i o n s were measured t o t h e n e a r e s t 0.1 mm by m i c r o m e t e r .  These were  used l a t e r t o c a l c u l a t e a c t u a l i n i t i a l m o i s t u r e c o n t e n t s and s p e c i f i c gravities. A l l " g r e e n " specimens had m o i s t u r e c o n t e n t s above 25% and were t h e r e b y beyond t h e r a n g e o f t h e p o w e r - l o s s meter s c a l e .  Only t h e r e s i s t -  ance t y p e m o i s t u r e meter was used i n t h i s i n s t a n c e . Measurements were t a k e n w i t h t h e e l e c t r o d e a l i g n e d p a r a l l e l t o t h e g r a i n d i r e c t i o n and p e r p e n d i c u l a r t o t h e r a d i a l f a c e s . The d e p t h s o f p e n e t r a t i o n were 0.5 and 1.2 cm.  The f o r m e r measurements a t 1/5 o f t h e specimen t h i c k n e s s  c o r r e s p o n d e d t o t h e o v e r - a l l m o i s t u r e c o n t e n t ( 1 1 ) . The l a t t e r was a measure o f t h e c o r e m o i s t u r e c o n t e n t .  D i f f e r e n c e s between t h e two m e a s u r e -  ments were g e n e r a l l y s m a l l , i n d i c a t i n g a f a i r l y even m o i s t u r e g r a d i e n t . S u b s e q u e n t l y , t h e specimens were c o n d i t i o n e d s t e p w i s e t o nominal 19%, 12% abd 6% m o i s t u r e c o n t e n t s . The specimen p i e c e s were p l a c e d on wooden t r a y s w i t h v i n y l s c r e e n bottom, which p r o v i d e d good v e n t i l a t i o n . T r a y s were s t a c k e d i n s i d e an Aminco c o n s t a n t t e m p e r a t u r e and h u m i d i t y (CTH) chamber.  Each c o n d i t i o n i n g t o o k two t o t h r e e weeks.  ment o f m o i s t u r e c o n t e n t u n i f o r m i t y was compromised to c o n s e r v e t i m e .  The r e q u i r e -  a l i t t l e i n order  S t a b l e m o i s t u r e c o n t e n t l e v e l s were e s t a b l i s h e d a s  shown': by f a i r l y c o n s t a n t specimen w e i g h t a t c o n s e c u t i v e w e i g h i n g s . F o l l o w i n g each c o n d i t i o n i n g , t h e specimens were weighed i n g r o u p s of f o u r as r e p r e s e n t i n g t h e same r a d i a l s e r i e s s t r i p s .  Use o f t h e r e s i s t -  ance t y p e m o i s t u r e meter f o l l o w e d t h e same p r a c t i c e as d e s c r i b e d f o r t h e  24 "green" c o n d i t i o n , e x c e p t i n a d d i t i o n t o measurements made on t h e r a d i a l f a c e s , t a n g e n t i a l f a c e s were i n v e s t i g a t e d as w e l l .  The nominal 6% m o i s t u r e  l e v e l was beyond t h e c a p a c i t y o f t h e r e s i s t a n c e m o i s t u r e m e t e r . A l l measurements were made a t 21 °C. The p o w e r - l o s s  type m o i s t u r e meter had an 8.6 cm d i a m e t e r c i r c u l a r  e l e c t r o d e , a n d demanded an even l a r g e r specimen s u r f a c e t o accommodate the e l e c t r o d e .  T h i s posed a problem on matched r a d i a l s e r i e s measurements,  s i n c e t h e l a r g e s t d i a m e t e r o f t h o s e stems sampled was l e s s than 40 cm. One p i t h t o p e r i p h e r y r a d i a l s e r i e s c o u l d a t most accommodate two measurements which were f a r from a d e q u a t e f o r e s t a b l i s h i n g w i t h i n stem d a t a o f analytical value. To overcome t h e p r o b l e m , a novel method o f specimen a r r a n g e m e n t was devised.  The group o f f o u r specimens were a l i g n e d s i d e by s i d e , e x p o s i n g  e i t h e r r a d i a l o r t a n g e n t i a l s u r f a c e s t o p r o v i d e a 10 x 10 cm s u r f a c e . P r e s s u r e was e x e r t e d l a t e r a l l y t o m i n i m i z e gaps between s p e c i m e n s . The measurements c o u l d then be made on t h i s i m p r o v i s e d s u r f a c e .  A f t e r measure-  ments were t a k e n on both r a d i a l f a c e s , t h e specimens were t u r n e d 90° and a g a i n measurements were made on t h e two t a n g e n t i a l s u r f a c e s .  The method  not o n l y p r o v i d e d a f e a s i b l e way t o a s s e s s a r a d i a l s e r i e s and p r o v i d e matched a n i s o t r o p y measurements, b u t by s h i f t i n g specimen a l i g n m e n t s d e f e c t s c o u l d be e x c l u d e d from d i r e c t l y c o n t a c t i n g t h e e l e c t r o d e ,  minor  thereby  m i n i m i z i n g i n f l u e n c e o f t h e wood d e f e c t s . P r e l i m i n a r y t e s t s were r u n t o d e t e r m i n e t h e e f f e c t s o f " r e c o n s t i t u t i n g " a board by p u t t i n g specimens back t o g e t h e r .  Two-and-half centimeter  t h i c k l o d g e p o l e p i n e boards were a l t e r n a t e l y c u t i n t o 10 x 10 cm b l o c k s and s p e c i m e n - s i z e  pieces.  The c o m p a r a b l e s e t s o f b l o c k s and  p i e c e s were c o n d i t i o n e d a t t h r e e d i s t i n c t h u m i d i t y l e v e l s  specimen-size  (approximately  25 0%, 50% and 100%).  A f t e r one month t h e p o w e r - l o s s meter r e a d i n g s on  each s e t showed v e r y s m a l l d e v i a t i o n s between i n t a c t b l o c k s and r e c o n stituted blocks. The p o w e r - l o s s m o i s t u r e meter was d e s i g n e d t o work on a 5 cm t h i c k board.  S i n c e 2.5 cm t h i c k specimens were u s e d , a s t y r o f o a m i n s u l a t i n g  p i e c e was p l a c e d beneath t h e specimens t o p r e v e n t any e x t e r n a l i n f l u e n c e from c a u s i n g e r r a t i c r e s u l t s . 3.3.3 O v e n - d r y i n g and c a l c u l a t i o n s E v e n t u a l o v e n - d r y i n g was used t o o b t a i n specimen w e i g h t s .  Follow-  i n g t h e l a s t b a t c h o f m o i s t u r e measurements, specimens were s t a c k e d i n ovens w i t h w i r e mesh s e p a r a t i n g e a c h l a y e r f o r b e t t e r v e n t i l a t i o n .  The  ovens were a d j u s t e d and m a i n t a i n e d a t 102°C f o r t h r e e d a y s . A g l o v e box w i t h a i r l o c k was s e t up, and a w e l l a d j u s t e d e l e c t r i c a l b a l a n c e was p l a c e d i n s i d e t h e g l o v e box.  Glass trays containing s i l i c o n  g e l and P^Og were put under t h e f a l s e bottom o f t h e g l o v e box and a i r l o c k t o g i v e a d r y atmosphere  inside.  A f t e r removal from ovens, s p e c i -  mens were p u t i n a d e s c c i c a t o r and c a r r i e d t o t h e g l o v e box, where t h e y were s t o r e d i n t h e a i r - l o c k and a l l o w e d t o c o o l . Then t h e i n d i v i d u a l specimen p i e c e s were weighed. on a t a p e - r e c o r d e r .  The b a l a n c e r e a d i n g s were r e c o r d e d v o c a l l y  At t h e end o f each b a t c h o f measurements, t h e d a t a  were t r a n s c r i b e d o n t o d a t a s h e e t s . F o r c o n t r o l , t h e a c t u a l m o i s t u r e c o n t e n t (U) was computed as f o l l o w s : U% =  Wu - Wo Wo  x 100  [3]  where: Wu  w e i g h t w i t h m o i s t u r e c o n t e n t U ( o r i g i n a l w e i g h t ) ; and  Wo  weight f o l l o w i n g oven-drying (41),  26  Data on wood s p e c i f i c g r a v i t y (6) were c a l c u l a t e d a s f o l l o w s : •W o G =  9  V  —  where: W  Q  = o v e n - d r y w e i g h t ; and  Vg = " g r e e n " d i m e n s i o n o f t h e s p e c i m e n .  M  27  4,0  RESULTS  Data o f t h e e x p e r i m e n t were t r e a t e d a c c o r d i n g t o t h e f o l l o w i n g three headings.  Raw d a t a n o t d i s c u s s e d here appear i n A p p e n d i c e s IV  and V. 4.1  Specific Gravity S p e c i f i c g r a v i t i e s o f specimens based on o v e n - d r y w e i g h t and g r e e n  volume were o b t a i n e d t h r o u g h u s e o f E q u a t i o n [ 4 ] . T h e r e were f o u r measurements f o r each s e t o f specimens.  S i n c e the power-loss meter  head c o v e r e d a l l f o u r p i e c e s , t h e mean o f t h e f o u r measurements was used t o r e p r e s e n t t h e s p e c i f i c g r a v i t y o f a p a r t i c u l a r specimen s e t .  Varia-  t i o n s i n s p e c i f i c g r a v i t i e s w i t h i n t h e specimen s e t c o u l d be s u b s t a n t i a l . In some c a s e s up t o 0.04 i n v a l u e , even though t h e y came from t h e same l o n g i t u d i n a l s t r i p and were no more t h a n 30 cm a p a r t . The c a u s e s o f t h i s v a r i a t i o n were m a i n l y m i n o r d e f e c t s and uneven wood t e x t u r e . The s p e c i f i c g r a v i t i e s o f t h e samples a r e p r e s e n t e d i n Appendix V. accompanying t h e p b w e r ^ l o s s meter r e s u l t s . The s p e c i f i c g r a v i t y v a r i a t i o n s f o r between s p e c i e s and w i t h i n l o d g e p o l e p i n e c o m p a r i s o n s a r e p r e s e n t e d i n F i g 2 and 3. The p l o t t e d p o i n t s a r e t h e means o f two r e p l i c a t e s .  In some c a s e s t h e r e were s u b s t a n t i a l  d i f f e r e n c e s between t h e two r e p l i c a t e s , due t o uneven growth p a t t e r n s and t h e sample s e l e c t i o n imposed.  P l o t s a r e i n t e n d e d t o show t h e t r e n d  o f s p e c i f i c g r a v i t y v a r i a t i o n s w i t h i n t h e stem a t d i f f e r e n t h e i g h t l e v e l s and wood z o n e s .  In l o d g e p o l e p i n e r e a c t i o n wood samples, o n l y t h e com-  p r e s s i o n wood r e s u l t s a r e p l o t t e d , i n s t e a d o f a v e r a g i n g o p p o s i t e wood v a l u e s w i t h t h o s e o f c o m p r e s s i o n wood.  28 4.2  R e s i s t a n c e Type M o i s t u r e Meter R e s i s t a n c e m e t e r d a t a a r e p r e s e n t e d i n Appendix  IV.  T h r e e sample  m o i s t u r e c o n t e n t l e v e l s were e x a m i n e d , i . e . , " g r e e n " , nominal 19% and 12%.  I t i s beyond t h e l i m i t o f the r e s i s t a n c e m e t e r t o measure m o i s t u r e  c o n t e n t a t 6%, hence no d a t a were c o l l e c t e d a t t h a t l e v e l . The r e l a t i o n s h i p between e l e c t r i c c o n d u c t i v i t y and'wood m o i s t u r e c o n t e n t i s known t o be c u r v e l i n e a r w i t h t h e i n f l e c t i o n p o i n t around f i b e r s a t u r a t i o n p o i n t o f t h e wood.  the  S i n c e i n t h i s e x p e r i m e n t o n l y two  l e v e l s o f m o i s t u r e c o n t e n t were below the f i b e r s a t u r a t i o n p o i n t , i t i s not f e a s i b l e t o f i t a l i n e r e g r e s s i n g m e t e r r e a d i n g s on m o i s t u r e c o n t e n t . Freehan'djrregression l i n e s intended f o r q u a l i t a t i v e d i s c u s s i o n of the d a t a a r e p r e s e n t e d i n F i g 4 and 5.  In t h e s e , the l i n e s were f i t t e d  through  d a t a p o i n t s o f t h e two m o i s t u r e c o n t e n t l e v e l s below the f i b e r s a t u r a t i o n p o i n t and a p o i n t i n t h e v a c i n i t y o f t h e f i b e r s a t u r a t i o n . 4.3  Power-loss  Meter  Data on p o w e r - l o s s m o i s t u r e meter measurements a t nominal c o n t e n t o f 19%, 12% arid 6% a r e p r e s e n t e d i n Appendix  moisture  V.  R e s u l t s o f a n a l y s i s o f v a r i a n c e and c o v a r i a n c e t a b l e s f o r between s p e c i e s , between t r e e s and w i t h i n stem f a c t o r s a r e p r e s e n t e d i n T a b l e 1 t o 19.  These t a b l e s a r e n o t i n c l u s i v e , and a l l t h e n o n - s i g n i f i c a n t i n t e r -  a c t i o n s have been e n t e r e d i n t o t h e e r r o r terms.  The power o f t h e a n a l y s i s  o f v a r i a n c e was n o t i d e a l , due t o empty c e l l s , unequal  replications,  m i s s i n g l e v e l s and u n c e r t a i n t y i n e x p e c t e d mean s q u a r e s used f o r t e s t i n g each f a c t o r . Many o f t h e s e problems were i n t r i n s i c and u n a v o i d a b l e , l i k e t a p e r i n g o f t r e e s , unequal growth p a t t e r n s t o t h e l e f t and r i g h t o f the p i t h and l a r g e d e f e c t s . S i m p l e and m u l t i p l e r e g r e s s i o n s o f i m p o r t a n t i n d e p e n d e n t v a r i a b l e s a r e  p r e s e n t e d as F i g 6 t o 10. C a l i b r a t i o n c h a r t s g e n e r a t e d by t h e s e r e g r e s s i o n e q u a t i o n s a r e p r e s e n t e d as T a b l e . 2 0 t o 23.  Comparison w i t h d a t a p r o v i d e d by t h e manufac  t u r e r and t h a t e s t a b l i s h e d by B r a m h a l l and Salamon ( T l ) a r e g i v e n .  3.Q  5.0 D i s c u s s i o n 5.1  Moisture Contents; The c h o i c e o f m o i s t u r e c o n t e n t l e v e l s i n t h e e x p e r i m e n t , i . e . ,  nominal 19%, 12% and 6% r e p r e s e n t e d a range i n which lumber m a n u f a c t u r i n g , s e a s o n i n g and t r a n s p o r t a t i o n a r e most l i k e l y t o be i n t e r e s t e d .  The 12%  l e v e l may r e p r e s e n t t h e a i r - d r i e d m o i s t u r e c o n t e n t . The o v e n - d r y i n g method used i n o b t a i n i n g m o i s t u r e c o n t e n t v a l u e s i s c o n v e n t i o n a l and e a s i l y a p p l i c a b l e . Most woods i n v e s t i g a t e d i n t h i s s t u d y have e x t r a n e o u s m a t e r i a l s , some f r a c t i o n o f which must have been l o s t during drying to give s l i g h t l y higher apparent moisture values (41). S i n c e t h e r e i s no easy way o f e s t a b l i s h i n g t h i s d e v i a t i o n , no a t t e m p t was made t o c o r r e c t t h e oven-dry m o i s t u r e v a l u e s .  Conditioned values  were 1 t o 2% h i g h e r than t h e i n t e n d e d o r t h e nominal m o i s t u r e c o n t e n t levels.  More time might have been taken t o a l l o w specimens t o r e a c h eq-  u i l i b r i u m c o n d i t i o n s i n t h e CTH chamber.  T h i s was e v i d e n c e d by t h e mois-  t u r e g r a d i e n t o f 0.1 t o 0.5% i n t h e r e s i s t a n c e meter measurements t a k e n a t 1/5 o f specimen t h i c k n e s s and a t t h e c o r e . The sample " g r e e n " c o n d i t i o n t u r n e d o u t t o be l o w e r than from f r e s h l y f e l l e d t r e e s , a consequence o f s a m p l i n g l o g d e c k s .  W h i l e some r e s u l t s  were b a r e l y above t h e f i b e r s a t u r a t i o n p o i n t , o t h e r s ranged up t o 150% o r so f o r some sapwood specimens.  N e v e r t h e l e s s , t h e purpose o f t h e s t u d y was  s e r v e d by p r o v i d i n g a m o i s t u r e c o n t e n t l e v e l above t h e f i b e r s a t u r a t i o n p o i n t i n a l l c a s e s and a b a s i s f o r " g r e e n " volume used i n s p e c i f i c g r a v i t y calculations. 5.2  Specific Gravities* From r e v i e w o f l i t e r a t u r e , t h e s u b j e c t o f d e n s i t y o r s p e c i f i c g r a v i t y  31  effects on power factor of wood is observed to be controversial.  Some  investigators considered that the correlation between power factor and wood density is weak or ambiguous (29, '41/, 54).  On the other hand, ev-  idence exists in support of a positive correlation between the two (63, 70,'78).  In any event, inclusion of specific gravity as an independent  variable may help to account for part of the variability experienced with power-loss meter readings. As showed in Fig  2 and 3, there are substantial specific gravity  variations among species, within lodgepole pine species, and with height levels and wood zones within individual stems. Such variations in conifers have been studied extensively by various authors.  A general pattern for coniferous wood has evolved as:  in radial  direction, specific gravity either increases all the way from pith to periphery or decreases from pith in the corewood zone then increases to a maximum at the periphery; while in axial direction, specific gravity decreases from the base to top of these stems (69).  Some of the factors  affecting specific gravity of wood have been established.  For instance,  diameter, volume to age ratio and age of Douglas-Fir contribute significantly to its specific gravity (57). is confusing.  However, lack of agreement in certain cases  Radial direction specific gravity variations of Douglas-fir  have been reported as increasing from pith to periphery, as decreasing from pith in the corewood zone then increasing to a maximum at the periphery, and as increasing in the corewood zone then remaining constant or decreasing slightly at the periphery (71, 72, 76). Due to these uncertainties, references made for specific gravity variations should be treated with some reservation.  The variability of wood  power factor at various stem levels as related to specific gravity tions will be discussed.  varia-  32 5.3  The Power F a c t o r When an a l t e r n a t e c u r r e n t i s a p p l i e d t o two p a r a l l e l p l a t e s , w i t h  a d i e l e c t r i c sandwiched between, t h e e l e c t r i c c u r r e n t can be imaged as a c o n t i n u o u s s i n e wave.  In an i d e a l c o n d e n s e r , t h e c h a r g i n g c u r r e n t on  t h e p l a t e s u r f a c e s l e a d s t h e a p p l i e d a l t e r n a t i n g p o t e n t i a l by 9 0 ° .  When  t h e f r e q u e n c y o f t h e c u r r e n t i n c r e a s e s , t h e c h a r g i n g c u r r e n t w i l l be s l i g h t l y o u t o f phase, and a d s o r p t i v e p o l a r i z a t i o n o c c u r s . t h e n l e a d s t h e v o l t a g e by (  The c u r r e n t  - S ); S i s c a l l e d the l o s s a n g l e .  The  t a n g e n t o f t h i s a n g l e i s termed d i s s i p a t i o n f a c t o r o r l o s s t a n g e n t . complementary  angle of  0 i s the phase a n g l e .  The  The c o s i n e o f 0 i s c a l l e d  t h e "power f a c t o r " , s i n c e i t e x p r e s s e s t h e r a t i o o f power d i s s i p a t e d t o t h e t o t a l power l e d i n t o the system. t o c o s 0.  When & i s s m a l l , t a n $ i s e q u i v a l e n t  T h e power f a c t o r o f wood i n c r e a s e s w i t h i t s m o i s t u r e c o n t e n t  a t a g i v e n f r e q u e n c y , and the m o i s t u r e meter was d e s i g n e d a c c o r d i n g t o this principle. Power f a c t o r o f wood i s a l s o dependent on o t h e r f a c t o r s l i k e tempe r a t u r e and f r e q u e n c y .  P r o p e r c h o i c e o f f r e q u e n c y t o e n s u r e maximum  r e s p o n s e between t h e power f a c t o r and m o i s t u r e c o n t e n t o f wood and c o n v e r t i n g c h a r t s accommodated w i t h t e m p e r a t u r e changes a r e i m p o r t a n t c o n s i d e r a t i o n s i n t h e d e s i g n and use o f t h e p o w e r - l o s s t y p e m o i s t u r e m e t e r . 5.4  M o i s t u r e Meter V a r i a b l e s A main o b j e c t i v e o f t h i s s t u d y was t o i n v e s t i g a t e some o f t h e v a r i -  a b l e s a s s o c i a t e d w i t h e l e c t r i c a l means o f m o i s t u r e measurements.  Exter-  nal f a c t o r s l i k e t e m p e r a t u r e , f r e q u e n c y , wood t r e a t m e n t and w e a t h e r i n g may have s i g n i f i c a n t i n t e r a c t i o n s w i t h meter r e a d i n g s , but were beyond t h e scope o f t h e p r e s e n t s t u d y .  33  De Zeeuw (19) p o i n t e d o u t the u n i q u e n e s s o f i n d i v i d u a l p i e c e s o f wood.  C e l l w a l l s a r e v a r i a b l e i n c h e m i c a l c o m p o s i t i o n and i n o r g a n i z a t i o n  on t h e m o l e c u l a r l e v e l , compounded w i t h v a r i a t i o n s between s e v e r a l p a r t s o f i n d i v i d u a l t r e e s i n c e l l s i z e s , w a l l t h i c k n e s s and t i s s u e o r g a n i z a t i o n . A l l t h e s e f e a t u r e s d i r e c t l y i n f l u e n c e i t s p h y s i c a l b e h a v i o u r and cause v a r i a b i l i t y i n t h e s e l a t t e r c h a r a c t e r i s t i c s . Many o f t h e c o n t r o v e r s i a l q u e s t i o n s o f wood v a r i a b i l i t y may s i m p l y be i n t e r - s p e c i f i c d i f f e r e n c e s o r o t h e r v a r i a t i o n s which cause d i s c r e p a n c i e s as r e p o r t e d i n the l i t e r a t u r e . 5.4.1  Between s p e c i e s v a r a i b i l i t y The r e s i s t a n c e m o i s t u r e meter i s i n f a c t a microampere meter which  r e g i s t e r s t h e s t r e n g t h o f e l e c t r i c c u r r e n t p a s s i n g between t h e two e l e c t r o d e p i n s . The meter i s l o g a r i t h m i c a l l y s c a l e d t o accommodate t h e l o g a r i t h m r e l a t i o n s h i p between d.e. r e s i s t a n c e o f wood and i t s m o i s t u r e content.  For measurements below t h e f i b e r s a t u r a t i o n p o i n t and above c a .  1% m o i s t u r e c o n t e n t , a good l i n e a r r e l a t i o n s h i p can be o b t a i n e d between meter r e a d i n g s and m o i s t u r e c o n t e n t s .  However, the d a t a here tended t o  u n d e r e s t i m a t e t h e a c t u a l m o i s t u r e c o n t e n t by 2 t o 6% (Appendix IV and F i g 4 and 5 ) . ; S i n c e t h e meter had been c a l i b r a t e d w i t h s t a n d a r d r e s i s t a n c e s b e f o r e t h e e x p e r i m e n t , t h e cause o f t h e s e d i s c r e p a n c i e s may come from c o n f i g u r a t i o n o f the e l e c t r o d e p i n s . Through p r o l o n g e d usage, t h e t i p s o f the p i n s may wear o f f and become b l u n t , c r e a t i n g s m a l l c r e v i c e s between t h e e l e c t r o d e and wood s u b s t a n c e . exposed d e c r e a s e s c o n t a c t a r e a .  A l s o , t h i s reduced area of pins These would i n c r e a s e r e s i s t a n c e and lower  the readings. K o z l i k (42) used b o t h r e s i s t a n c e and p o w e r - l o s s type m o i s t u r e meters t o measure m o i s t u r e c o n t e n t o f w e s t e r n hemlock (Tsuga h e t e r o p h y l l a ( R a f . ) S a r g . ) d i m e n s i o n lumber.  The f o r m e r t e n d e d t o u n d e r e s t i m a t e a c t u a l  34 moisture content s l i g h t l y . In g e n e r a l , r e s i s t a n c e m o i s t u r e m e t e r r e a d i n g s showed l e s s v a r i a t i o n compared w i t h t h e p o w e r - l o s s m e t e r .  Nevertheless,  e n c e s d i d e x i s t , as showed i n F i g 4.  between s p e c i e s d i f f e r -  These d i f f e r e n c e s a r e s t r o n g enough  t o overshadow t h e s p e c i f i c g r a v i t y e f f e c t ( 5 3 , 91) and have w a r r a n t e d t h e use o f a d j u s t i n g t a b l e s f o r d i f f e r e n t s p e c i e s . I n t e r s p e c i f i c v a r i a t i o n s d i d not quite follow the s p e c i f i c g r a v i t y r a n k s shown i n F i g 2.  Besides moisture  c o n t e n t , t h e most s i g n i f i c a n t  v a r i a b l e a f f e c t i n g e l e c t r i c a l r e s i s t a n c e o f wood i s t h o u g h t t o be t h e amount o f w a t e r - s o l u b l e  e l e t r o l y t e s ( 8 2 ) . T h e r e b y , v a r i a t i o n may be  a t t r i b u t e d l a r g e l y t o extraneous material content.  O r g a n i c p o l a r sub-  s t a n c e s would have some e f f e c t on e l e c t r i c a l r e s i s t a n c e o f t h e wood. r a n k i n g i n F i g 4 seems t o match s u s p e c t e d e x t r a c t i v e c o n t e n t s  The  ( 1 5 , 69, 7 5 ) ,  a t l e a s t t o some e x t e n t . V e n k a t e s w a r a n (92) p r o p o s e d t h a t wood l i g n i n c o n t e n t has a s i g n i f i c a n t e f f e c t on wood e l e c t r i c a l r e s i s t i v i t y .  The c o r r e l a t i o n between  l i g n i n c o n t e n t and e l e c t r i c a l c o n d u c t i v i t y (d.e.) o f wood was a p o s i t i v e l i n e a r one. The l i g n i n c o n t e n t s o f t h e s p e c i e s i n v e s t i g a t e d here a r e q u i t e s i m i l a r . A c c o r d i n g t o l i t e r a t u r e v a l u e s t h e y a r e i n t h e range o f 26 t o 30% (69,79).  T h e r e f o r e , t h e l i g n i n c o n t e n t may n o t have c o n t r i b u t e d  much t o t h e s p e c i e s v a r i a t i o n s . Kollmann (39) c o n s i d e r e d t h a t numerous wood p r o p e r t i e s , such a s d e n s i t y , f i b e r l e n g t h , v e s s e l w i d t h v a r i a t i o n , s o r p t i o n and r h e o l o g y o f wood f o l l o w G a u s s i a n d i s t r i b u t i o n s . E l e c t r i c a l p r o p e r t i e s o f wood a r e profoundly i n t e r r e l a t e d with such p r o p e r t i e s , t h e r e f o r e , should e x h i b i t normal d i s t r i b u t i o n .  35 The a n a l y s i s o f v a r i a n c e o f p o w e r - l o s s meter r e s u l t s ( T a b l e showed h i g h l y s i g n f i c a n t d i f f e r e n c e between s p e c i e s .  1)  In o r d e r t o e l i -  m i n a t e t h e p o s s i b l e s p e c i f i c g r a v i t y e f f e c t as the c a u s e o f t h i s d i f f e r e n c e , c o v a r i a n c e a n a l y s e s were c a r r i e d o u t , u s i n g s p e c i f i c g r a v i t y o f e a c h specimen as c o v a r i a t e ( T a b l e 2 ) .  values  The c o r r e l a t i o n c o e f f i c i e n t  between p o w e r - l o s s meter r e a d i n g s and s p e c i f i c g r a v i t i e s was  .3494 and  t h e F v a l u e was s t i l l h i g h l y s i g n i f i c a n t . A draw-back o f the  covariance  a n a l y s i s , as used h e r e , was the r e q u i r e m e n t of homogeneous s l o p e s f o r regression equations of individual c e l l s . t i o n s per c e l l f o r an F - t e s t .  T h e r e were not enough r e p l i c a -  S i n c e many f a c t o r s were p r e s e n t e d  a n a l y s i s of variance t a b l e , the r e l i a b i l i t y of the covariance became d o u b t f u l .  Nevertheless,  the r e s u l t s may  s i g n i f i c a n c e o f d i f f e r e n c e s between s p e c i e s .  i n the  analysis  l e n d some support t o the The S t u d e n t i z e d  Newman-Keul-  m u l t i p l e range t e s t i n u n a d j u s t e d ( s p e c i f i c g r a v i t y ) d a t a showed t h a t t h e r e were no two s p e c i e s having s i m i l a r r e s p o n s e t o p o w e r - l o s s m o i s t u r e meter r e a d i n g s a t c o m p a r a b l e m o i s t u r e r a n g e s . P a r a l l e l i s m o f p o w e r - l o s s m o i s t u r e meter r e a d i n g s and s p e c i f i c g r a v i t y g r a p h s ( F i g 6 and 8 vs.- F i g 2 ) , s u g g e s t e d t h a t s p e c i f i c g r a v i t y may some i n f l u e n c e on t h e power f a c t o r of wood.  U n l i k e the r e s u l t s  have  obtained  by L i n ( 5 4 ) , w h i c h i n d i c a t e p r a c t i c a l l y no e f f e c t o f d e n s i t y on power f a c t o r o f wood, the m u l t i p l e r e g r e s s i o n s f o r a l l t r e e s c a r r i e d out here i n d i c a t e d t h a t s p e c i f i c g r a v i t y was an i n d e p e n d e n t v a r i a b l e making s i g n i f i c a n t c o n t r i b u t i o n t o the r e g r e s s i o n e q u a t i o n .  Quantities obtained  by  m u l t i p l y i n g a p p a r e n t m o i s t u r e p e r c e n t a g e o f the specimen and i t s s p e c i f i c g r a v i t y , which i s an e x p r e s s i o n  of a b s o l u t e amount o f water per u n i t  volume, was the s i n g l e most i m p o r t a n t i n d e p e n d e n t v a r i a b l e i n the  regression,  accounting  potential  f o r 88.1% o f the t o t a l v a r i a b i l i t y . I n c l u s i o n of o t h e r  36 i n d e p e n d e n t v a r i a b l e s , as m o i s t u r e c o n t e n t and i t s t r a n s f o r m e d form, m o i s t u r e c o n t e n t s q u a r e d , a c c o u n t e d f o r 91.7% o f t h e t o t a l v a r i a b i l i t y . In m u l t i p l e r e g r e s s i o n e q u a t i o n s w i t h a l l p o t e n t i a l i n d e p e n d e n t  vari-  a b l e s f o r c e d i n , t h e l e a s t s i g n i f i c a n t v a r i a b l e s may be dropped o u t stepwise.  Here, t h e p r o d u c t o f m o i s t u r e c o n t e n t and s p e c i f i c g r a v i t y  was t h e f i r s t i n d e p e n d e n t v a r i a b l e t o drop o u t . T h i s q u a n t i t y was a l i n e a r c o m b i n a t i o n o f m o i s t u r e c o n t e n t and s p e c i f i c g r a v i t y and was highly c o r r e l a t e d with e i t h e r moisture content or s p e c i f i c g r a v i t y . The r e m a i n i n g p o r t i o n o f v a r i a b i l i t y unaccounted f o r by t h e r e g r e s s i o n e q u a t i o n seems t o have a r i s e n i n p a r t from e x p e r i m e n t a l e r r o r s and some o t h e r v a r i a b l e s n o t i n v e s t i g a t e d i n t h i s s t u d y .  The p r e c i s i o n o f t h e  i n s t r u m e n t was n o t i d e a l and may have c o n t r i b u t e d t o e x p e r i m e n t a l e r r o r s . The p r e s e n c e o f specimen, d e f e c t s c o u l d cause some d e v i a t i o n , a s well.. C o n t r i b u t i o n o f o t h e r v a r i a b l e s was n o t i n v e s t i g a t e d i n t h i s s t u d y and t h e r e must be complex i n t e r a c t i o n s among t h e s e .  Only s p e c u l a t i o n s  based on l i t e r a t u r e i n f o r m a t i o n w i l l be o f f e r e d f o r t h e e n s u i n g d i s c u s s i o n t o e x p l a i n some d i f f e r e n c e s o b s e r v e d .  A p a r t i c u l a r tendency o f v a r i a t i o n  u s u a l l y r e s u l t e d from o v e r a l l e f f e c t s o f t h e s e v a r i a b l e components. The power f a c t o r o f wood was s u s p e c t e d t o be a f f e c t e d by a n a t o m i c a l and c h e m i c a l f e a t u r e s o f t h e wood. . Among t h e s e wood c h a r a c t e r i s t i c s , f i b e r l e n g t h , c e l l u l o s e c r y s t a l ! i n i t y , l i g n i n c o n t e n t , amount and t y p e o f i n o r g a n i c i n c l u s i o n s and e x t r a c t i v e c o n t e n t have been r e p o r t e d a s m a j o r v a r i a b l e s (14,78,92,94,95).  T h e i r i n v o l v e m e n t i n wood power f a c t o r v a r i -  a b i l i t y has been d i s c u s s e d e a r l i e r .  A b r i e f d i s c u s s i o n o f these v a r i a b l e s  as r e l a t e d t o s p e c i e s o f t h e p r e s e n t s t u d y i s now i n c l u d e d . T r a c h e i d l e n g t h s f o r a l l f o u r s p e c i e s s t u d i e d were more o r l e s s comp a r a b l e , as t h e y a p p e a r i n l i t e r a t u r e d a t a ( 6 9 , 8 3 ) . In c a s e no d i r e c t  37  r e f e r e n c e was a v a i l a b l e f o r a p a r t i c u l a r s p e c i e s , data f o r o t h e r s p e c i e s o f t h e same genus a r e a v a i l a b l e . Even v a r a i t i o n s w i t h i n s p e c i e s c o u l d be considerable. v a r i a t i o n (19).  Growth f a c t o r s and g e n e t i c f a c t o r s c o n t r i b u t e most t o t h i s T r a c h e i d l e n g t h v a r a i t i o n may r e f l e c t o t h e r f a c e t s o f  v a r a i t i o n l i k e ash c o n t e n t and e x t r a c t i v e c o n t e n t ( 1 4 ) , but p r o b a b l y  has  l i t t l e s i g n i f i c a n c e o f i t s own. D i f f e r e n c e s i n c h e m i c a l c o m p o s i t i o n c o u l d be the most  important  v a r i a b l e . s t i 1 1 t o be a c c o u n t e d f o r . C e l l u l o s e c r y s t a l l i n i t y o f wood has been shown t o r e l a t e p o s i t i v e l y w i t h wood d e n s i t y ( 5 0 , 6 7 ) .  Power f a c t o r o f wood, i n t u r n , was r e l a t e d  negatively with c e l l u l o s e c r y s t a l l i n i t y (95).  T h e r e f o r e , there i s con-  f l i c t here and t h e s p e c i f i c g r a v i t y e f f e c t would be p a r t l y c a n c e l l e d . Data o f c e l l u l o s e c r y s t a l l i n i t y f o r t h e s p e c i e s s t u d i e d was not a v a i l a b l e . As m e n t i o n e d above, l i g n i n c o n t e n t s o f t h e s p e c i e s examined would be e x p e c t e d t o be s i m i l a r . A c c o r d i n g t o V e n k a t e s w a r a n ( 9 2 ) , t h e r e i s n e g a t i v e c o r r e l a t i o n between l i g n i n c o n t e n t and d i e l e c t r i c p e r m i t t i v i t y ( d i e l e c t r i c c o n s t a n t ) o f t h e wood.  The e v i d e n c e from c o n d e n s e r  paper  r e s e a r c h i n d i c a t e s t h a t l i g n i n has a d e t r i m e n t a l e f f e c t on power f a c t o r . Thus, t h e h i g h e r t h e l i g n i n c o n t e n t , the h i g h e r t h e power f a c t o r o f wood ( 9 6 ) . Ash c o n t e n t s o f c o n i f e r o u s woods a r e u s u a l l y q u i t e m i n u t e , n o r m a l l y 0.1 t o 0.5% o f t h e oven-dry weight o f d o m e s t i c c o n i f e r o u s woods ( 2 0 ) . Even so t h i s c o u l d c o n t r i b u t e s i g n i f i c a n t l y t o d i e l e c t r i c l o s s o f c e l l u lose materials (96).  M o n o v a l e n t i o n s o f the ash had the most d e t r i m e n t a l  e f f e c t on power l o s s , w h i l e b i v a l e n t i o n s were f a r l e s s h a r m f u l .  The  l a t t e r p r e s e n t e d i n low c o n c e n t r a t i o n s , however, c o u l d r e d u c e power f a c t o r s l i g h t l y under c e r t a i n temperature  and f r e q u e n c y c o n d i t i o n s ( 6 ) .  -38 Noble f i r ( A b i e s p r o c e r a Rend.), grand f i r ( A b i e s g r a n d i s D o u g l . ) , D o u g l a s - f i r , s l a s h p i n e ( P i n u s e l l i o t t i Engelm) and Engelmann s p r u c e ( P i c e a e n g a l m a i i P a r r y ) have ash c o n t e n t s r e p o r t e d a t 0.4, 0.4, 0.2 and 0.2%, r e s p e c t i v e l y (20,69).  0.2  Of t h e s e , c a l c i u m , p o t a s s i u m and magnesium  g e n e r a l l y c o m p r i s e d 70% o f the t o t a l ash c o n t e n t .  The c o m p o s i t i o n c o u l d  depend much on growth f a c t o r s and g e o g r a p h i c d i s t r i b u t i o n and c o u l d be q u i t e variable (17).  The h i g h l y s i g n i f i c a n t r e l a t i o n s h i p o f ash c o n t e n t t o power  f a c t o r w i t h c o n d e n s e r p a p e r s does not n e c e s s a r i l y mean t h a t i t w i l l d i c t a t e power f a c t o r o f wood s i g n i f i c a n t l y , e s p e c i a l l y a t h i g h m o i s t u r e c o n t e n t . M o i s t u r e c o n t e n t s o f c o n d e n s e r p a p e r r e s e a r c h were u s u a l l y s e t a t o v e n - d r y c o n d i t i o n t o e l i m i n a t e e x t e r n a l v a r i a b l e s . The amount o f ash and i t s comp o s i t i o n i n wood may s t i l l a f f e c t d i e l e c t r i c l o s s o f wood a t low m o i s t u r e content.  The h i g h e r ash c o n t e n t o f f i r wood, however, seemed n o t to  affect i t s variability in this  way.  Vermaas (94) p r o v i d e d some e v i d e n c e t h a t a l c o h o l - b e n z e n e s o l u b l e c o n t e n t a f f e c t e d ^ d i e l e c t r i c l o s s o f the wood.  He p o i n t e d o u t t h a t d i -  e l e c t r i c l o s s i s i n the form o f h e a t a b s o r b e d by wood, and t h a t h e a t i n g r e s u l t s from d i p o l e movements.  P o l a r e x t r a c t i v e s c o u l d be the s o u r c e o f  such d i p o l e s and c o n t r i b u t e t o the l o s s t a n g e n t .  The v a l u e o f l o s s t a n -  gent increased l i n e a r l y with e x t r a c t i v e content i n r a d i a l d i r e c t i o n at m o i s t u r e range between 0 and 25%, w h i l e i n t a n g e n t i a l d i r e c t i o n , t h e r e was l i t t l e c o r r e l a t i o n a t low m o i s t u r e c o n t e n t s and s l i g h t d e c r e a s e i n l o s s tangent with Increasing e x t r a c t i v e content l e v e l s . The e x t r a c t i v e c o n t e n t s f o r the s p e c i e s examined were g i v e n a s : l o d g e p o l e p i n e ( P i n u s c o n t o r t a D o u g l . ) , 4.7% ( a c e t o n e f r a c t i o n ) ; w h i t e s p r u c e ( P i c e a g l a u c a (Moench.) V o s s . ) , 1.98%  (acetone f r a c t i o n ) (75);  D o u g l a s - f i r , 4.45% ( e t h a n o l - b e n z e n e ) ; and f o r n o b l e f i r ,  2.7%  39 (ethanol-benzene) (69),  A l t h o u g h t h e d a t a came from d i f f e r e n t s o u r c e s  and r e p r e s e n t d i f f e r e n t e x t r a c t i o n s , t h e e x t r a c t i v e c o n t e n t s  showed  s i m i l a r rank t o between s p e c i e s p o w e r - l o s s m o i s t u r e m e t e r r e a d i n g s . The r e g r e s s i o n l i n e f o r D o u g l a s - f i r has a u n i q u e s l o p e , which was q u i t e d i f f e r e n t from t h e r e s t o f t h e samples examined ( F i g 6 and 8 ) . C o n s i d e r t h a t D o u g l a s - f i r samples had the h i g h e s t a v e r a g e s p e c i f i c g r a v i t y , a b r u p t e a r l y w o o d - l a t e w o o d t r a n s i t i o n s and some p o l y p h e n o l i c e x t r a c t i v e s w h i c h a r e a b s e n t i n the o t h e r woods examined. may have c o n t r i b u t e d t o the d i f f e r e n c e s o b s e r v e d . has c o m p a r a t i v e l y  A l l these  Specific gravity  l e s s i n f l u e n c e on power f a c t o r than m o i s t u r e  content.  At low m o i s t u r e c o n t e n t , however, i t c o n t r i b u t e d v e r y s i g n i f i c a n t l y t o higher readings  ( l a r g e r i n t e r c e p t , F i g 6 and 8 ) , but a t h i g h  moisture  c o n t e n t i t s e f f e c t d i m i n i s h e d and c a u s e d t h e r e g r e s s i o n l i n e t o be more f l a t than f o r other 5.4.2  species.  Between t r e e v a r i a b i l i t y As shown i n F i g 5, r e s i s t a n c e meter r e a d i n g v a r i a t i o n s between f o u r  l o d g e p o l e p i n e samples were q u i t e s m a l l .  No r e l a t i o n between s p e c i f i c  g r a v i t y r a n k i n g ( F i g 3) and the meter r e a d i n g v a r i a t i o n s was d i s c e r n i b l e . Poor r e l a t i o n s h i p o f wood e l e c t r i c a l r e s i s t a n c e t o s p e c i f i c g r a v i t y changes r e n d e r s t h e r e s i s t a n c e meter more p r e c i s e than the p o w e r - l o s s m o i s t u r e meter ( 4 1 ) . S i n c e wood p r o p e r t i e s e x h i b i t G a u s s i a n d i s t r i b u t i o n , v a r i a t i o n s among samples a r e i n e v i t a b l e . To e s t a b l i s h a r e l i a b l e c o n v e r s i o n p o w e r - l o s s meter r e a d i n g s , l a r g e sample s i z e s are c a l l e d f o r .  for  Means  and s t a n d a r d d e v i a t i o n s o b t a i n e d t h r o u g h t h e s e s a m p l i n g s would be u s e f u l to e s t a b l i s h confidence  i n t e r v a l s f o r the  The a n a l y s i s o f v a r i a n c e p r e s e n t e d  estimations.  i n T a b l e 3 showed t h a t h i g h l y  40 s i g n i f i c a n t d i f f e r e n c e s e x i s t e d among l o d g e p o l e p i n e t r e e p o w e r - l o s s measurements s t u d i e d .  Covariance a n a l y s i s (Table 4 ) , using s p e c i f i c  g r a v i t y a s t h e c o v a r i a t e showed poor  c o r r e l a t i o n between m e t e r r e a d i n g s  and s p e c i f i c g r a v i t i e s , w i t h c o e f f i c i e n t o f c o r r e l a t i o n , r = 0.1286. In a d d i t i o n , no F t e s t f o r comparing t h e r e g r e s s i o n e q u a t i o n o f each c e l l was a v a i l a b l e , so t h e u s e f u l n e s s o f c o v a r i a n c e a n a l y s i s was d o u b t f u l . The S t u d e n t i z e d Newman-Keul m u l t i p l e range t e s t i n d i c a t e d t h a t l o d g e p o l e p i n e No. 1 and No. 2, a l s o l o d g e p o l e p i n e No. 3 and No. 4 belonged t o t h e same homogeneous s u b s e t s , and were n o t s i g n i f i c a n t l y d i f f e r e n t , b u t l o d g e p o l e p i n e No. 1 and No. 2 were s i g n i f i c a n t l y d i f f e r e n t f r o m l o d g e p o l e p i n e No. 3 and No. 4. D i f f e r e n c e s between l o d g e p o l e p i n e t r e e s were p a r t l y a t t r i b u t a b l e t o s p e c i f i c g r a v i t y v a r i a t i o n s among them.  Data needed t o t e s t homo-  g e n e i t y among s l o p e s were l a c k i n g , t h e r e f o r e s l o p e s were n o t compared. The v a r i a t i o n s among s l o p e s o f F i g 9 seemed t o be l e s s d i v e r g e n t a s compared w i t h t h e between s p e c i e s v a r i a t i o n s . The p o o l e d d a t a f o r l o d g e p o l e p i n e t r e e s i s a l s o p l o t t e d a s F i g 8. 2 The R v a l u e s f o r p o o l e d d a t a were f a i r l y good, i n d i c a t i n g good f i t o f the r e g r e s s i o n equation. 5.4.3  Within tree height v a r i a b i l i t y The " g r e e n " sample m o i s t u r e v a r i e d , and m e t e r r e a d i n g s a t t h i s l e v e l  were n o t c o m p a r a b l e .  A t nominal 19% and 12% m o i s t u r e l e v e l s t h e r e was a  tendency f o r measurements t a k e n a t t h e l o w e s t t r e e segment o f a l l s p e c i e s t o be s l i g h t l y h i g h e r t h a n measurements from h i g h e r segments,  The d i f f e r -  e n c e s , n e v e r t h e l e s s , were s m a l l and d i d not a f f e c t p r e c i s i o n . C o n i f e r o u s woods w i t h r e g u l a r r e s i n d u c t s have h i g h e r r e s i n c o n t e n t s a t t h e stem base.  Presumably t o t a l a s h c o n t e n t has a s i m i l a r d i s t r i b u t i o n  (35),  which c o n t r i b u t e s to h i g h e r r e a d i n g s f o r measurements made low  i n the t r u n k . From a n a l y s i s o f v a r i a n c e ( T a b l e 5 to 19) f o r a l l the s p e c i e s s t u d i e d , the between h e i g h t l e v e l p o w e r - l o s s m e t e r v a r i a t i o n s were mostly not s i g n i f i c a n t , with or without s p e c i f i c g r a v i t y adjustment ( a g a i n , the a n a l y s i s o f c o v a r i a n c e may n o t be v a l i d ) .  The t r e n d o f  v a r i a t i o n s i n m e t e r r e a d i n g s taken a t d i f f e r e n t h e i g h t l e v e l s had the q u a l i t a t i v e c h a r a c t e r i s t i c o f b e i n g h i g h e r a t the two e x t r e m i t i e s , i . e . , t h e f i r s t and f i f t h s e g m e n t s , w h i l e minima o c c u r r e d a t i n t e r m e d i a t e s e g ments, u s u a l l y below l i v e crown samples.  T h i s s l i g h t v a r i a t i o n may  be  a c c o u n t e d f o r i n p a r t by c o n s i d e r i n g s p e c i f i c g r a v i t y v a r i a t i o n . F u r thermore, t r a c h e i d l e n g t h s i n c r e a s e d i r e c t l y w i t h i n c r e a s i n g h e i g h t i n t h e stem t o a maxima p a r t way up the t r u n k (below the l i v e crown),  then  f u r t h e r d e c r e a s e w i t h i n c r e a s i n g h e i g h t t o the top o f the t r e e (19,69). Longer f i b e r s have g i v e n lower d i e l e c t r i c l o s s i n papers ( 1 4 ) , which i s i n k e e p i n g w i t h the p a t t e r n s o f v a r i a t i o n h e r e . For p r a c t i c a l purposes, i t i s j u s t i f i a b l e to c l a i m that height l e v e l s c o n t r i b u t e d l i t t l e to p o w e r - l o s s m e t e r v a r i a t i o n s . 5.4.4  Within tree radial v a r i a b i l i t y L i t t l e has been done on wood zone v a r i a t i o n i n r e l a t i o n t o i t s  e l e c t r i c a l p r o p e r t i e s . B e l d i e t aj_. (4) found t h a t d i f f e r e n c e s i n d i e l e c t r i c - V p r o p e r t i e s r e s u l t i n g from s t r u c t u r a l v a r i a t i o n w i t h i n a g i v e n oak stem was n e g l i g i b l e . No p r e v i o u s work on c o n i f e r o u s wood w i t h i n t r e e v a r i a t i o n has been found. R e f e r r i n g t o F i g 4 and 5, the dashed l i n e s i n d i c a t e sapwood r e a d i n g s which were s l i g h t l y h i g h e r than the c o r r e s p o n d i n g s o l i d l i n e  heartwood  42 readings.  D i f f e r e n c e s were more p r o m i n e n t a t low m o i s t u r e c o n t e n t s ,  i . e . , nominal 12% m o i s t u r e c o n t e n t .  The wood zone d i f f e r e n c e s were  e s p e c i a l l y w e l l d e f i n e d i n the cases o f w h i t e s p r u c e , D o u g l a s - f i r and lodgepole pine.  S i n c e no sapwood r e a d i n g s a t green c o n d i t i o n were n e a r  f i b e r s a t u r a t i o n p o i n t , a h i g h e r l e v e l f o r sapwood was not a v a i l a b l e , c a u s i n g l i n e s t o be t r u n c a t e d . The q u a l i t a t i v e d i f f e r e n c e i n r e s i s t a n c e m o i s t u r e meter r e a d i n g s i n r a d i a l d i r e c t i o n may r e s u l t from some c h e m i c a l v a r i a t i o n , which w i l l be d i s c u s s e d more f u l l y .  The v a r i a t i o n i n t h i s case was g e n e r a l l y l e s s  than 1% i n m o i s t u r e , as t r a n s l a t e d from the meter r e a d i n g .  I f the r e -  q u i r e m e n t f o r a c c u r a c y i s not so c r i t i c a l , t h i s wood zone v a r i a t i o n may be n e g l e c t e d . t h i s s o u r c e was  Compared w i t h between t r e e v a r i a t i o n , the amount from minor.  Corewood samples showed no d i s t i n c t d i f f e r e n c e from o t h e r heartwood samples a t low m o i s t u r e l e v e l , b u t r e a d i n g s tended to d e c r e a s e s l i g h t l y from t h e p i t h t o the end o f heartwood zones. A n a l y s i s o f v a r i a n c e ( T a b l e 1 to 19) i n d i c a t e d t h a t t h e r e were s i g n i f i c a n t d i f f e r e n c e s f o r wood zone samples  power-loss  measurements.  Sapwood samples had the h i g h e s t p o w e r - l o s s m e t e r r e a d i n g s , f o l l o w e d by corewood samples, then by d e c r e a s i n g o r d e r from i n n e r t o o u t e r h e a r t wood.  The t r e n d i s p r a c t i c a l l y the same as t h a t f o r r e s i s t a n c e m e t e r  readings. Examining the s p e c i f i c g r a v i t y graphs i n F i g 2 and 3, the h i g h e r r e a d i n g s i n sapwood can be a t t r i b u t e d i n p a r t t o h i g h e r s p e c i f i c g r a v i t i e s f o r w h i t e s p r u c e and D o u g l a s - f i r . F o r l o d g e p o l e p i n e t r e e s , t h e sapwood tended t o have lower s p e c i f i c g r a v i t y than the h e a r t w o o d .  R e a d i n g s , however,  43 showed t h e same t r e n d s as when sapwood zones had h i g h e r s p e c i f i c g r a v i t y . The u n d e r l y i n g c a u s a l f a c t o r s must come from a n a t o m i c a l and c h e m i c a l v a r i a t i o n s , p o s s i b l y as d i s c u s s e d i n t h e L i t e r a t u r e Review.  This p a r t i -  c u l a r e f f e c t c o n t r i b u t e d t o lower c o r r e l a t i o n c o e f f i c i e n t s between s p e c i f i c g r a v i t y and meter r e a d i n g s f o r l o d g e p o l e p i n e .  Subalpine f i r ,  on t h e o t h e r hand, showed corewood w i t h t h e h i g h e s t r e a d i n g s among radial series. C o n i f e r o u s wood t r a c h e i d l e n g t h v a r a i t i o n s i n r a d i a l d i r e c t i o n have been s t u d i e d e x t e n s i v e l y .  A t any g i v e n h e i g h t , t r a c h e i d l e n g t h i n c r e a s e s  r a p i d l y a c r o s s t h e corewood zone then i n c r e a s e s more s l o w l y u n t i l a m a x i mum i s reached„ mum l e n g t h .  a f t e r w h i c h t h e r e w i l l be f l u c t u a t i o n about a mean m a x i -  E v e n t u a l l y i n v e r y o l d t r e e s , t h e t r a c h e i d l e n g t h may d e c r e a s e  s l i g h t l y (69).  L i t e r a t u r e i n f o r m a t i o n on t h e s p e c i e s s t u d i e d was: f o r  l o d g e p o l e p i n e , D o u g l a s - f i r and w h i t e spruce t r a c h e i d l e n g t h s ' i n c r e a s e d from p i t h t o p e r i p h e r y (19,83,87);  w h i l e f o r s u b a l p i n e f i r , t r a c h e i d I;  l e n g t h s i n c r e a s e d from p i t h t o about 10 cm d i a m e t e r , then s l i g h t l y outward ( 3 6 ) .  T h i s t r e n d would e x p l a i n t h e h i g h e r  decreased power-loss  meter r e a d i n g s f o r corewood i n p a r t , b u t would c o n t r a d i c t t h e h i g h e r meter r e a d i n g s f o r sapwood.  E v i d e n t l y , o t h e r f a c t o r s must a l s o be c o n s i d e r e d .  P r e s t o n et_ al_. (73) compared C r o s s and Bevan c e l l u l o s e c r y s t a l l i n i t y taken from d i f f e r e n t r i n g s o f monterey p i n e ( P i n u s r a d i a t a D. Don). They found c r y s t a l l i n t i y d e c r e a s e d from p i t h t o p e r i p h e r y .  L e e ( 5 0 ) , on t h e  o t h e r hand, s t u d i e d t h e s a m e ' r e l a t i o n s h i p , u s i n g h o l o c e l l u l o s e s and p u l p s from western hemlock and found t h a t c r y s t a l l i n i t y i n c r e a s e d from p i t h t o periphery.  T h e s e c o n f l i c t i n g r e s u l t s may be s i m p l y due t o s p e c i e s d i f f e r -  ences o r c e l l u l o s e p r e p a r a t i o n d i f f e r e n c e s . The c e l l u l o s e c o n t e n t i n r a d i a l d i r e c t i o n tended t o i n c r e a s e from t h e p i t h o u t w a r d , then l e v e l o f f  44 g r a d u a l l y (34,87).  I f t h e f r a c t i o n s f o r c r y s t a l l i n e and amorphous  c e l l u l o s e were r e l a t i v e l y c o n s t a n t , t h e n t h e amount o f c r y s t a l l i n e c e l l u l o s e would be e x p e c t e d t o be h i g h e r a t t h e p e r i p h e r y .  T h i s would  mean a t r e n d f o r d e c r e a s i n g power f a c t o r from t h e p i t h outward. Red p i n e ( P i n u s r e s i n o s a L . ) , Norway s p r u c e ( P i c e a a b i e s L. ( K a r s t . ) ) and Japanese r e d p i n e ( P i n u s d e n s i f l o r a L.) have been shown t o have dec r e a s i n g l i g n i n c o n t e n t from  the p i t h to p e r i p h e r y (26,27,48).  Again,  t h i s i m p l i e s a d e c r e a s i n g t r e n d f o r d.e. c o n d u c t i v i t y and power f a c t o r o f wood from t h e p i t h t o p e r i p h e r y .  A l l t h e s e c o n s i d e r a t i o n s seem t o  i n d i c a t e t h a t sapwood s h o u l d have lower r e s i s t a n c e and p o w e r - l o s s meter r e a d i n g s than t h a t o f sapwood. On t h e g r o u n d s t h a t s p e c i f i c g r a v i t i e s were h i g h e r i n t h e sapwood, t h e argument would h o l d f o r D o u g l a s - f i r and w h i t e s p r u c e , but l e a v e l o d g e p o l e p i n e samples a  paradox.  E x t r a n e o u s s u b s t a n c e s may be t h e r e m a i n i n g key t o t h e v a r i a t i o n . Ash d i s t r i b u t i o n i n r a d i a l d i r e c t i o n has been shown t o be u n i f o r m i n p i n e wood ( 4 4 ) , whereas i n a n o t h e r s t u d y ( 4 3 ) , K a r e l i a n p i n e ( P i n u s spp.)  was  shown t o have h i g h e s t ash c o n t e n t a t t h e e x t e r n a l l a y e r o f sapwood, w i t h t h e e x c e p t i o n o f c a l c i u m and manganese which were h i g h e s t i n heartwood. S i n c e c a l c i u m has been shown t o have l i t t l e e f f e c t on d i e l e c t r i c l o s s (6) and manganese i s t h o u g h t t o be c h e l a t e d by wood s u b s t a n c e s and t h e r e b y does not p a r t i c i p a t e i n charge c a r r y i n g m i g r a t i o n under an e l e c t r i c f i e l d ( 4 7 ) , t h e s e s h o u l d not much i n f l u e n c e wood e l e c t r i c a l p r o p e r t i e s . (5) s t u d i e d t h e d i s t r i b u t i o n o f ash and phosphorus s p r u c e ( s c i e n t i f i c names not g i v e n ) .  Bergstrom  i n Swedish p i n e and  He found c o n s i d e r a b l e v a r i a t i o n i n ash  c o n t e n t among t r e e s , as a f f e c t e d by l o c a l i t y and o t h e r f a c t o r s . c o n t e n t was f i v e t i m e s h i g h e r i n t h e sapwood than heartwood.  Phorphorus  Heartwood  had h i g h e r a l k a l i e a r t h m e t a l s , w h i l e t h e sapwood had h i g h e r a l k a l i m e t a l s .  45 M c M i l l i n ( 5 6 ) , on t h e o t h e r hand, found t h a t the ash c o n t e n t o f l o b l o l l y p i n e ( P i n u s t a e d a L.) tended t o d e c r e a s e from t h e p i t h outward.  However,  he d i d note t h a t sodium c o n t e n t o f t h e wood showed n e g a t i v e c o r r e l a t i o n with s p e c i f i c g r a v i t y .  If his f i n d i n g i s a p p l i c a b l e to lodgepole pine,  t h e lower s p e c i f i c g r a v i t y would s t i l l mean h i g h e r m o n o v a l e n t i o n c o n t e n t . S i n c e ash c o n t e n t has a s t r o n g i n f l u e n c e on both d.e. c o n d u c t i v i t y and d i e l e c t r i c power l o s s ( 7 7 , 9 6 ) , i t i s l i k e l y t h a t h i g h e r ash c o n c e n t r a t i o n s i n t h e sapwood zone c o n t r i b u t e s i g n i f i c a n t l y t o t h e h i g h e r r e a d i n g s o f r e s i s t a n c e and p o w e r - l o s s m o i s t u r e  meters.  O r g a n i c e x t r a c t i v e c o n t e n t s have been l o n g r e c o g n i z e d as c o n c e n t r a t e d i n t h e heartwood zone.  Campbell  e t al_. (15) compared wood zone r e s i n o u s  e x t r a c t s i n D o u g l a s - f i r . The e x t r a c t i v e c o n t e n t ( e t h a n o l - b e n z e n e )  was  found t o d e c r e a s e from t h e p i t h outward, b e i n g 6%, 5% and 2% f o r corewood, heartwood and sapwood, r e s p e c t i v e l y . The same p a t t e r n h o l d s f o r p i n e (75,87) and s p r u c e ( 9 7 ) .  P o l y p h e n o l s , such as d i h y d r o q u e r c e t i n i n  D o u g l a s - f i r , had a d i f f e r n t p a t t e r n .  T h i s i n c r e a s e d from p i t h t o t h e  t r a n s i t i o n zone o f heartwood and sapwood t h e n d e c r e a s e d r a p i d l y and d i s appeared i n t h e sapwood ( 2 4 ) .  I f a l l o t h e r v a r i a b l e s were c o n s t a n t , t h e  g e n e r a l t r e n d o f v a r i a t i o n due t o e x t r a c t i v e c o n t e n t would be t o d e c r e a s e power f a c t o r and d.e. c o n d u c t i v i t y from t h e p i t h outward. C o m p o s i t i o n and amount o f e x t r a c t i v e s a r e q u i t e v a r i a b l e ( 7 5 ) .  As an  example, r o s i n from c o n i f e r o u s wood i s a good i n s u l a t o r and d i e l e c t r i c , and can h e l p t o reduce d i e l e c t r i c l o s s e s . L i t e r a t u r e e v i d e n c e (49) showed t h a t a b i e t i c a c i d has a b e n e f i c i a l e f f e c t on r e d u c i n g d i e l e c t r i c l o s s . T h i s c o n t r a d i c t i o n may r e l a t e t o s t a t e i n wood, which i s d i s p e r s e d as a l i q u i d and i s e a s i l y p o l a r i z a b l e . In s o l i d r o s i n , r e s i n a c i d m o l e c u l e s a r e r i g i d l y h e l d i n a c r y s t a l l i n e l a t t i c e and can not c o n t r i b u t e t o p o l a r i z a t i o n  46  s  or i o n i z a t i o n phenomenon. In summary, the i n o r g a n i c ash c o n t e n t in- wood may be the s i n g l e , most important,  v a r i a b l e c o n t r o l l i n g unexplained  v a r i a b i l i t y o f p o w e r - l o s s and  d.e. r e s i s t a n c e r e a d i n g s i n the r a d i a l d i r e c t i o n .  Other v a r i a b l e s  may  f u r t h e r e f f e c t p a t t e r n s from the p i t h t o o u t e r heartwood. 5.4.5  Within tree  anisotropy.  A l t h o u g h measurements were taken on both r a d i a l and t a n g e n t i a l s p e c i men  f a c e s w i t h the d i r e c t c u r r e n t r e s i s t a n c e m e t e r , they were i n f a c t both  measured a l o n g the g r a i n .  V a r i a t i o n s among t h e s e two s e t s o f  readings  s i m p l y mean l o c a l i z e d m o i s t u r e c o n t e n t d i f f e r e n c e s and does not s i g n i f y a n i s o t r o p y between r a d i a l and t a n g e n t i a l d i r e c t i o n . A n a l y s i s o f v a r i a n c e r e s u l t s ( T a b l e s 1 t o 19) i n d i c a t e t h a t t h e r e were s i g n i f i c a n t d i f f e r e n c e s f o r p o w e r - l o s s m e t e r r e a d i n g s taken on r a d i a l and t a n g e n t i a l f a c e s .  T h i s c l e a r l y shows an a n i s o t r o p y e f f e c t .  The d i r -  e c t i o n o f e l e c t r i c a l f i e l d i n both cases was p e r p e n d i c u l a r t o the g r a i n direction.  Measurements \taken on r a d i a l f a c e s meant the f i e l d d i r e c t i o n  as t a n g e n t i a l , and v i c e .versa.-  Measurements f r o m r a d i a l d i r e c t i o n were  d i s t i n c t l y h i g h e r than c o r r e s p o n d i n g  measurements made i n t a n g e n t i a l d i r e c t i o n .  T h i s c o n f i r m s r e s u l t s o f s e v e r a l o t h e r s t u d i e s (45,65,74).  The i n t e r a c t i o n s  between- d i r e c t i o n s and m o i s t u r e c o n t e n t s are a l s o s i g n i f i c a n t . T h i s means t h a t the d i f f e r e n c e between d i r e c t i o n s changes w i t h c h a n g i n g m o i s t u r e  con-  tent. R e a s o n i n g b e h i n d the p o w e r - l o s s a n i s o t r o p i c phenomenon has n o t h i n g do w i t h the above m e n t i o n e d v a r i a b l e s . a n i s o t r o p y w i t h gross wood anatomy ( 8 8 ) .  Evidence  i n d i c a t e s dependency o f  Cell wall o r i e n t a t i o n rather  than m i c r o s c o p i c s t r u c t u r a l d i f f e r e n c e s i n wood, are t h o u g h t t o be the  to  47  cause o f a n i s o t r o p y ( 4 5 , 8 8 ) . In t a n g e n t i a l d i r e c t i o n , t h e r a y c e l l s r u n p a r a l l e l t o t h e e l e c t r i c a l f i e l d , whereas i n t h e r a d i a l d i r e c t i o n , t h e r a y c e l l s r u n p e r pendicular to the f i e l d direction.  Ray c e l l s a r e r i c h i n c e l l c o n t e n t s  which may be e a s i l y p o l a r i z a b l e under an a l t e r n a t i n g e l e c t r i c f i e l d . In t h e f o r m e r case t h e p o l a r i z a t i o n would e x h i b i t s t r a t a a l o n g t h e p l a n e of ray c e l l s .  In t h e l a t t e r c a s e , p o l a r i z a t i o n would be i n t h e same  d i r e c t i o n as t h e e l e c t r i c f i e l d , i n d u c e d resonance would i n c r e a s e power l o s s and r e n d e r r a d i a l d i r e c t i o n measurement h i g h e r t h a n t h o s e o f tangential direction. 5.4.6  Compression wood A r e a c t i o n wood sample was i n c l u d e d t o i n v e s t i g a t e t h e e f f e c t o f  h i g h l i g n i n c o n t e n t as f o u n d i n a s p e c i f i c wood zone on e l e c t r i c m o i s t u r e meter measurements.  A c c o r d i n g t o Venkateswaran  (92), higher l i g n i n  c o n t e n t i n c r e a s e d wood d.e. c o n d u c t i v i t y , t h u s a t t h e same m o i s t u r e c o n t e n t , c o m p r e s s i o n wood s h o u l d g i v e h i g h e r meter r e a d i n g s t h a n t h e c o r r e s p o n d i n g r e g u l a r wood.  Examining d a t a o f Appendix IV does n o t  show a n y pronounced d i f f e r e n c e on r e a c t i o n wood r e s i s t a n c e meter r e a d ings.  The c o r r e l a t i o n between l i g n i n c o n t e n t and s p e c i f i c c o n d u c t i v i t y  of wood must be weak, i n d e e d .  Under oven-dry c o n d i t i o n s wood l i g n i n  c o n t e n t may c o n t r i b u t e t o i t s d.e. c o n d u c t i v i t y . A t h i g h m o i s t u r e c o n t e n t s , however, t h e overwhelming l y mask t h e l i g n i n e f f e c t .  i n f l u e n c e o f moisture could complete-  T h i s argument i s s u p p o r t e d by t h e e v i d e n c e  t h a t o n l y a t nominal 12% m o i s t u r e c o n t e n t , d i d t h e measurements show a s l i g h t i n c r e a s e as compared w i t h a v e r a g e r e g u l a r wood r e a d i n g s .  48 The p o w e r ^ l o s s m e t e r r e a d i n g s on l o d g e p o l e p i n e c o m p r e s s i o n  wood  were n o t i c e a b l y h i g h e r t h a n t h e c o r r e s p o n d i n g l o d g e p o l e p i n e r e g u l a r wood samples.  As shown i n F i g 7 and 10, t h e i n t e r c e p t o f r e a c t i o n wood  p o w e r - l o s s m e t e r r e a d i n g r e g r e s s e d a g a i n s t m o i s t u r e c o n t e n t and m o i s t u r e c o n t e n t s q u a r e d , was h i g h e r t h a n o t h e r l o d g e p o l e p i n e samples.  Also,  i n A p p e n d i x V, t h e matched o p p o s i t e wood p r o v i d e d a f u r t h e r c o n t r a s t between t h e two. One r e a s o n f o r t h e d i f f e r e n c e s c o u l d be t h e much h i g h e r s p e c i f i c g r a v i t y o f compres'sion wood;. T h i c k w a l l , s m a l l l l u m e n c o m p r e s s i o n wood c e l l s g i v e h i g h e r wood s u b s t a n c e p e r u n i t volume, hence h i g h e r s p e c i f i c gravity.  L i g n i n c o n t e n t may be t h e c a u s a l f a c t o r i n h i g h e r m e t e r r e a d -  i n g s , b u t i t s e f f e c t i s confounded w i t h s p e c i f i c g r a v i t y . I t has been shown i n i n s u l a t i o n paper r e s e a r c h t h a t 3 t o 4% r e s i d u a l l i g n i n c o n t e n t i n k r a f t papers d i d n o t show a p p r e c i a b l e d e t e r i o r a t i o n in d i e l e c t r i c loss.  Further increase i n l i g n i n content started t o a f f e c t  paper d i e l e c t r i c l o s s e s ( 4 5 ) .  J u d g i n g from t h i s q u a n t i t a t i v e d i f f e r e n c e ,  wood l i g n i n c o n t e n t p r o b a b l y o n l y has a c o m p a r a t i v e l y small e f f e c t on power-loss meter readings. When o n l y m o i s t u r e c o n t e n t squared was p r e s e n t e d as an i n d e p e n d e n t v a r i a b l e i n t h e r e g r e s s i o n e q u a t i o n , c o e f f i c i e n t o f d e t e r m i n a t i o n (R ) was .9181. When s p e c i f i c g r a v i t y was a l s o e n t e r e d a s a n o t h e r  independent  v a r i a b l e , t h e c o e f f i c i e n t o f d e t e r m i n a t i o n t h e n i n c r e a s e d t o .9838. From t h e s e r e s u l t s , t h e r o l e o f s p e c i f i c g r a v i t y was q u i t e a p p a r e n t i n c o n t r i b u t i n g t o h i g h c o m p r e s s i o n wood p o w e r - l o s s meter r e a d i n g s . 5.5  R e g r e s s i o n s and Comparisons On t h e b a s i s o f i n d i v i d u a l t r e e s , r e g r e s s i o n e q u a t i o n s i n c l u d i n g  49  m o i s t u r e x o n t e n t , m o i s t u r e c o n t e n t squared and s p e c i f i c g r a v i t y as i n d e p e n d e n t v a r i a b l e s can d e s c r i b e p o w e r - l o s s m o i s t u r e m e t e r v a r i a b i l i t y w i t h o u t l a r g e e r r o r . The r e s i d u a l s ( d i f f e r e n c e s between d a t a p o i n t s and r e g r e s s i o n l i n e s ) o f t h e s e r e g r e s s i o n e q u a t i o n s f o r l o d g e p o l e p i n e No. 3 and No. 4, w h i t e s p r u c e and D o u g l a s - f i r were p l o t t e d w i t h m o i s t u r e c o n t e n t s . T h e s e showed e s s e n t i a l l y h o r i z o n t a l l y d i s t r i b u t e d d a t a .  No r e m a i n i n g  t r e n d s among t h e d a t a were d i s c e r n i b l e , i n d i c a t i n g t h a t no a d d i t i o n a l v a r i a b l e was needed t o improve the p r e d i c t i o n . W i t h i n t r e e v a r i a b i l i t y c o n t r i b u t e d t o d i s p e r s i o n o f t h e d a t a , and a d d i t i o n o f o t h e r v a r i a b l e s , i . e . , a n a t o m i c a l and c h e m i c a l v a r i a b i l i t y , would p r o b a b l y narrow t h e magnitude o f d i s p e r s i o n , but may not c o n t r i b u t e f u r t h e r t o i m p r o v i n g t h e p r e d i c t i o n . The e r r o r o f e s t i m a t e changed w i t h c h a n g i n g m o i s t u r e content levels.  The h i g h e r t h e m o i s t u r e c o n t e n t , t h e more d i s p e r s e d t h e  p o w e r - l o s s meter measurements. In t h e e x p e r i m e n t a l m o i s t u r e c o n t e n t r a n g e , q u a d r a t i c e q u a t i o n s o f m o i s t u r e c o n t e n t on m e t e r r e a d i n g s gave t h e b e s t f i t , i f s p e c i f i c g r a v i t y was n o t c o n s i d e r e d .  B l o d g e t t (7) r e p o r t e d t h a t t h e r e l a t i o n s h i p between  l o s s t a n g e n t ( t a n S)  and m o i s t u r e c o n t e n t (M) o f o i l i m p r e g n a t e d p a p e r  can be e x p r e s s e d a s : t a n 6=  a + bM  [5]  2  2  T h i s i s s i m i l a r t o the p r e s e n t s t u d y .  Here, R  values with moisture  c o n t e n t s q u a r e d as i n d e p e n d e n t v a r i a b l e were .94 f o r l o d g e p o l e p i n e p o o l e d d a t a , up t o .97 f o r i n d i v i d u a l l o d g e p o l e p i n e t r e e s , .95 f o r s u b a l p i n e f i r and ,90 f o r w h i t e s p r u c e . D o u g l a s - f i r a t .73,  The o n l y low value, was f o r  P e c u l i a r i t y of the D o u g l a s - f i r r e g r e s s i o n equation  has been e x p l a i n e d on t h e b a s i s o f s p e c i f i c g r a v i t y i n a p r e v i o u s s e c t i o n . U s i n g t h e m u l t i p l e r e g r e s s i o n e q u a t i o n s , i n v e r s e p r e d i c t i o n s were  50 p r o d u c e d , as summarized i n T a b l e 20 t o 23,  Powers-loss m e t e r r e a d i n g s  from 15 t o 34 and s p e c i f i c g r a v i t y range from 0.25 t o 0,49 f o r l o d g e p o l e p i n e p o o l e d d a t a , w h i t e s p r u c e , D o u g l a s - f i r and s u b a l p i n e f i r were o b t a i n e d . S p e c i f i c g r a v i t y r a n g e s for each s p e c i e s were c h o s e n and r e u s l t s a r e l i s t e d t o g e t h e r w i t h t h o s e o f Bramhall and Salamon (11) and as s u p p l i e d by t h e m a n u f a c t u r e r a t 21°C. These t a b l e s a r e not aimed a t r e p l a c i n g e x i s t i n g ones, s i n c e t h e sample s i z e was far from adequate f o r such p u r p o s e . show t h e v a r i a b i l i t y o f measurements.  The i d e a i s t o  B r a m h a l l and Salamon (11) gave  2 p e r c e n t v a r i a b i l i t y e i t h e r way f o r t h e i r t a b l e s . T h i s i s g e n e r a l l y c o r r e c t f o r most o f t h e r e a d i n g s , but s u b s t a n t i a l d i f f e r e n c e s  were  also  p r e s e n t h e r e , e s p e c i a l l y a t m o i s t u r e e x t r e m i t i e s . The l a r g e sample s i z e f o r l o d g e p o l e p i n e p r o v i d e d r e s u l t s comparable  t o t h o s e from o t h e r s o u r c e s ,  w h i l e w h i t e s p r u c e , D o u g l a s - f i r and s u b a l p i n e f i r showed more d e v i a t i o n , p r o b a b l y p a r t l y a t t r i b u t a b l e t o s m a l l e r sample s i z e s . Examining V shows t h a t D o u g l a s - f i r sapwood r e a d i n g s  were  t h a n t h e c o r r e s p o n d i n g heartwood r e a d i n g s .  Appendix  o f t e n immensely h i g h e r  When t a k i n g measurements  s t r a d l i n g d i f f e r e n t wood z o n e s , awareness o f t h i s k i n d o f v a r i a b i l i t y would h e l p i n making p r o p e r a d j u s t m e n t t o t h e r e a d i n g s and more a c c u r a t e results could arise. 5.6  F u r t h e r Work T h i s s t u d y r e p o r t s c e r t a i n e f f e c t s on e l e c t r i c a l m o i s t u r e m e t e r  measurements a t t r i b u t a b l e t o wood v a r i a b i l i t y . . Causal f a c t o r s f o r t h e s e have been s p e c u l a t e d t h r o u g h i n t e r p r e t a t i o n iof t h e l i t e r a t u r e . c a u s a l f a c t o r s need t o be f u r t h e r e x p l o r e d .  Such  For example, some c h e m i c a l  a n a l y s e s o f wood showing wide v a r i a t i o n may c o n t r i b u t e t o b e t t e r unders t a n d i n g , e s p e c i a l l y i f r e l a t e d t o more p r e c i s e e l e c t r i c a l measurements.  51 6.0  CONCLUSIONS  The study showed t h a t t h e r e a r e c e r t a i n t r e n d s o f v a r i a b i l i t y i n r e s i s t a n c e and p o w e r - l o s s type m o i s t u r e m e t e r measurements on  coniferous  woods^which can be summarized as f o l l o w s : 1.  The d i r e c t c u r r e n t r e s i s t a n c e type m o i s t u r e meter showed l e s s  unexplained  v a r i a b i l i t y i n measurement, and was not a f f e c t e d by s p e c i f i c  g r a v i t y d i f f e r e n c e s t o any d i s c e r n i b l e e x t e n t . e s t i m a t e the a c t u a l m o i s t u r e c o n t e n t s .  Readings t e n d e d t o under-  The r a d i o f r e q u e n c y  power-loss  m o i s t u r e meter, on the o t h e r hand, gave more v a r i a b l e r e s u l t s , and  was  much a f f e c t e d by sample s p e c i f i c g r a v i t y v a r i a t i o n s and o t h e r wood variables. 2.  By i n t r o d u c i n g m o i s t u r e c o n t e n t , s p e c i f i c g r a v i t y and  moisture  c o n t e n t s q u a r e d i n r e g r e s s i o n e q u a t i o n s , 96.48% o f the t o t a l v a r i a t i o n between samples from f o u r l o d g e p o l e p i n e t r e e s was a c c o u n t e d f o r .  The  same t e s t f o r woods from f o u r s p e c i e s gave 91.67% o f the v a r i a t i o n a c c o u n t e d for. 3.  T h e r e were s i g n i f i c a n t d i f f e r e n c e s between s p e c i e s f o r both types  of moisture meter.  V a r i a t i o n i n the r e s i s t a n c e type m e t e r may have been  due to d i f f e r i n g amounts o f e l e c t r o l y t e s i n the woods. 4.  T h e r e were m i n o r d i f f e r e n c e s between l o d g e p o l e p i n e t r e e r e s i s -  tance meter measurements, compared t o between s p e c i e s a d j u s t m e n t s .  Power-  l o s s meter v a r i a t i o n s were more p r o n o u n c e d , p a r t l y due t o s p e c i f i c g r a v i t y d i f f e r e n c e s among the l o d g e p o l e p i n e samples. 5.  H e i g h t w i t h i n t r e e c o n t r i b u t e d very l i t t l e v a r i a t i o n t o e i t h e r  m o i s t u r e m e t e r measurement. 6.  Radial d i r e c t i o n within tree d i d provide d i s c e r n i b l e v a r i a t i o n  52  f o r both t y p e s o f m o i s t u r e meter. Measurements t e n d e d t o be h i g h e r i n corewood, d e c r e a s e outward t o the heatwood-sapwood b o u n d a r y , then i n c r e a s e d t o a maximum i n sapwood.  Higher monovalent m e t a l l i c i o n  c o n c e n t r a t i o n s i n the sapwood may e x p l a i n t h e h i g h e r sapwood r e a d i n g s . 7.  T h e r e was a d i s t i n c t a n i s o t r o p i c phenomenon f o r p o w e r - l o s s  m e t e r measurements a t a l l m o i s t u r e l e v e l s .  R a d i a l d i r e c t i o n measurements  tended t o be h i g h e r than t h o s e made i n t a n g e n t i a l d i r e c t i o n . 8.  Only a t low m o i s t u r e c o n t e n t d i d r e s i s t a n c e m e t e r measurements  on compression wood show s l i g h t l y h i g h e r r e a d i n g s . Any c o r r e l a t i o n between l i g n i n c o n t e n t and wood d.e. c o n d u c t i v i t y w o u l d seem t o be o v e r shadowed by m o s t u r e . H i g h e r p o w e r - l o s s m o i s t u r e m e t e r r e a d i n g s on comp r e s s i o n wood c o u l d have been due t o h i g h e r s p e c i f i c g r a v i t y o f t h e samples.  53 7.0  LITERATURE CITED  1.  A m e r i c a n S o c i e t y f o r T e s t i n g M a t e r i a l s . 1972. Methods o f t e s t f o r m o i s t u r e c o n t e n t o f wood. ASTM D e s i g . D2016-72T.  2.  Anon. 1955. Wood Handbook. No. 72. pp. 48-52.  3.  B a r k a s , W. W., Hearmon, R. F. S. and 6. H. P r a t t . 1943. r e s i s t a n c e o f wood. N a t u r e 151:83-84.  4.  B e l d i , F., B a l i n t , J . , S z a b o , 0. and B. R u z s a . 1968. D i e l e c t r i c p r o p e r t i e s o f v a r i o u s oak s p e c i e s . H o l z R o h - W e r k s t o f f . 26(3):89-95.  5.  B e r g s t r o m , H. 1959. The ash and p h o s p h o r u s c o n t e n t o f c o n i f e r o u s woods. Svensk P a p p e r s t i d n . 62:160-161.  6.  B o b r o v , A . I . , B a l a s h o v a , V. 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Source o f v a r i a t i o n  Df  Mean squares  Between s p e c i e s H e i g h t w i t h i n t r e e (H/T) Sample / h e i g h t (S/H/T) M o i s t u r e c o n t e n t (MC) Tree x MC H/T x MC S/H/T x MC R a d i a l vs_. t a n g e n t i a l D i r e c t i o n x MC Error Total  4 16 59 2 8 32 118 1 2 657 899  850 .09 24 .03 16 .10 12077 .00 140 .90 3 .47 4 .67 54 .61 8 .93 0 .63  Test term  F  +  Height/tree Sample/H/T  35.37 1.49 25.59 19203.98 244.05 5.52 7.43 86.84 14.20  Significance  **N.S. ** ** ** ** ** ** **  S t u d e n t i z e d Newman-Keul's t e s t , l e v e l o f s i g n i f i c a n c e = 0.05 Species l o d . p i n e Rw. l o d . p i n e No. 4 Frequencies 48 210 Means 29.33 26.27 Any two means d i f f e r s i g n i f i c a n t l y .  D-fir 216 25.92  * i n d i c a t e s i g n i f i c a n c e a t 0.0 5 l e v e l ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l N.S. i s n o t s i g n i f i c a n t . +  D e s i g n a t e term f o r F - t e s t .  Blank i n d i c a t e s t h e t e s t term i s " E r r o r " .  a-fir 180 24.27  w. s p r u c e 246 22.22  T a b l e 2. A n a l y s i s o f c o v a r i a n c e t a b l e f o r between s p e c i e s p o w e r - l o s s m e t e r measurements. S p e c i f i c g r a v i t y i s t h e c o v a r i a t e . L o d g e p o l e p i n e No. 4, l o d g e p o l e p i n e r e a c t i o n wood, w h i t e s p r u c e , D o u g l a s - f i r and s u b a l p i n e f i r d a t a were used. Source o f v a r i a t i o n  Df  Mean squares  T e s t term*  Between s p e c i e s H e i g h t w i t h i n t r e e (H/T) S a m p l e / h e i g h t (S/H/T) M o i s t u r e c o n t e n t (MC) T r e e x MC H/T x MC S/H/T x MC R a d i a l vs_. t a n g e n t i a l D i r e c t i o n x MC Error  4 16 59 2 8 32 118 1 2 656  61.64 5.57 11.78 12068.00 141.73 3.80 4.76 54.61 8.93 0.45  Height/tree Sample/H/T  F  11.06 0.48 26.12 26771.97 313.42 8.43 10.56 121.15 19.81  Common s l o p e o f a d j u s t m e n t = 33 .53 S t u d e n t i z e d Newman-Keul's Species Frequencies A d j u s t e d means  1. p i n e 4 210 25.71  t e s t , l e v e l o f s i g n i f i c a n c e = 0.05 1. p i n e Rw. 48 25 .42  a-fir 180 24.65  w. spruce 246 24.59  D-fir 216 24.31  Means u n d e r l i n e d by t h e same l i n e a r e n o t s i g n i f i c a n t l y d i f f e r e n t from each o t h e r . * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t . """Designate term f o r F - t e s t .  Blank i n d i c a t e s t h e t e s t term i s " E r r o r " ,  Significance  **  N.S.  ** ** ** ** ** ** **  Table 3. Analysis of variance table for within lodgepole pine regular wood power-loss meter measurements. Source of variation Between tree Height within tree (H/T) Sample/height (S/H/T) Moisture content Tree x MC H/T x MC S/H/T x MC Radial vs_. tangential Direction x MC Error Total  Df 3 15 55 2 6 30 no 1 2 591 815  Mean squares 328.40 10.74 4.49 . 15244.00 19.61 2.72 2.48 45.74 9.42 0.33  Test term  +  Height/tree Sample/H/T  F 30.58 2.39 13.47 45773.92 58.88 8.18 7.44 137.35 28.30  Significance  ** * ** ** ** ** ** ** **  Studentized Newman-Keul 's test, level of significance = 0.05 Trees Frequencies Means  1. pine 3 204 26.59  1. pine 4 210 26.27  1. pine 2 204 24.43  1. pine 1 198 24.08  Means underlined by the same line are not significantly different from each other. * indicate significance at 0.05 level. ** indicate significance at 0.01 level. N.S. indicate not significant designate term for F-test.  Blank indicates the test term is "Error".  CTl CO  T a b l e 4. A n a l y s i s o f c o v a r i a n c e t a b l e f o r w i t h i n l o d g e p o l e p i n e r e g u l a r woods power-loss meter measurements. C o v a r i a t e i s s p e c i f i c g r a v i t y . Source o f v a r i a t i o n  Df  Between t r e e H e i g h t w i t h i n t r e e (H/T) S a m p l e / h e i g h t (S/H/T) M o i s t u r e c o n t e n t (MC) T r e e x MC H/T x MC S/H/T x MC R a d i a l y_£. t a n g e n t i a l D i r e c t i o n x MC Error  3 15 55 2 6 30  no  1 2 590  Mean squares 25.71 5.52 4.87 15244.00 19.71 2.83 2.47 45.74 9.42 0.28  Test term  +  Height/tree Sample/H/T  Common s l o p e f o r a d j u s t m e n t = 23.38 S t u d e n t i z e d Newman-Keul's t e s t , l e v e l o f s i g n i f i c a n c e = 0.05 Trees 1. p i n e 3 1. p i n e 4 1. p i n e 2 1. p i n e 1 Frequencies 204 210 204 198 A d j u s t e d means 26.05 25.95 24.89 24.51 U n d e r l i n e d means a r e n o t s i g n i f i c a n t l y d i f f e r e n t from one a n o t h e r . * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t . d e s i g n a t e term f o r F - t e s t .  B l a n k i n d i c a t e s t h e t e s t term i s " E r r o r " .  F 4.66 1.13 17.25 53953.42 69.75 10.03 8.74 118.17 33.35  Significance  *  N.S.  ** ** ** ** ** ** **  T a b l e 5.  A n a l y s i s o f v a r i a n c e f o r l o d g e p o l e p i n e No. 1 power-loss meter measurements.  Source o f v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l vs.- t a n g e n t i a l D i r e c t i o n x MC Error Total  Df 3 13 2 6 26 1 2 144 197  Mean s q u a r e s 7.03 5.04 3749.10 1.57 5.25 5.47 3.60 2.14  Test term  F  +  Sample/H  1.39 2.36 1755.27 0.74 2.46 2.56 1.68  Significance N.S.  ** **  N.S.  **  N.S. N.S.  T a b l e 6. A n a l y s i s o f c o v a r i a n c e f o r l o d g e p o l e p i n e No. 1 power-loss meter measurements. is specific gravity. Source o f v a r i a t i o n  Df  Mean squares  Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l vs.- t a n g e n t i a l D i r e c t i o n x MC Error  3 13 2 6 26 1 2 143  5.52 4.49 3749.70 1.56 5.22 5.47 3.60 2.13  Common s l o p e o f adjustment  = 14.79  Test  term  +  Sample/H  * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S^. i n d i c a t e n o t s i g n i f i c a n t . +  D e s i g n i a t e term f o r F - t e s t .  Blank i n d i c a t e s t h e t e s t term i s " E r r o r " .  F 1.23 2.10 1758.79 0.73 2.45 2.56 1.69  Covariate  Significance N.S.  * **  N.S. **  N.S. N.S.  T a b l e 7.  A n a l y s i s o f v a r i a n c e t a b l e f o r l o d g e p o l e p i n e No. 2 p o w e r - l o s s m e t e r measurements.  Source of v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l vs^ t a n g e n t i a l D i r e c t i o n x MC Error Total T a b l e 8. A n a l y s i s o f c o v a r i a n c e is specific gravity. Source o f v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l vs.- t a n g e n t i a l D i r e c t i o n x MC Error  Df  Mean squares  4 14 2 8 28 1 2 144 203  4.59 5.15 3562.60 0.40 1.65 13.05 2.03 0.26  Test term  F  +  Sample/H  0.89 20.20 13968.61 • 1.58 6.46 51.17 7.96  Df  Mean squares  4 14 2 8 28 1 2 143  3.97 5.32 3564.00 0.39 1.66 13.05 2.03 0.24  Test term  +  Sample/H  * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t . term f o r F - t e s t .  N.S.  ** **  N.S.  ** ** **  f o r l o d g e p o l e p i n e No. 2 p o w e r - l o s s meter measurements.  Common s l o p e f o r a d j u s t m e n t = 17.12  designate  Significance  B l a n k i n d i c a t e s t h e t e s t term i s " E r r o r " .  F 0.75 22.36 14991.77 1.62 6.98 54.90 8.54  Covariate  -Significance N.S.  ** **  N.S.  ** ** **  T a b l e 9.  A n a l y s i s o f variance t a b l e f o r lodgepole  Source o f v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l vs^. t a n g e n t i a l D i r e c t i o n x MC Error Total Studentized Heights Frequencies Means  p i n e No. 3 p o w e r - l o s s meter measurements.  Df  Mean squares  T e s t term  4 14 2 8 28 1 2 144 203  12.41 2.66 3468.50 3.50 2.82 9.84 3.35 0.44  Sample/H  Significance 4.67 6.00 7838.53 7.90 6.37 22.23 7.56  Newman-Keul's t e s t , l e v e l o f s i g n i f i c a n c e = 0.05 1  54 27.30  Means u n d e r l i n e d  5  30 26.81  3  42 26.50  4  36 ' 26.17  2  42 26.00  by t h e same l i n e a r e not s i g n i f i c a n t l y d i f f e r e n t from each o t h e r .  * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t . +  *  ** ** ** ** ** **  D e s i g n i a t e term f o r F - t e s t .  Blank i n d i c a t e s t h e t e s t term i s " E r r o r " .  T a b l e 10. A n a l y s i s o f c o v a r i a n c e is specific gravity. Source of v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l y_£. t a n g e n t i a l D i r e c t i o n x MC Error  f o r l o d g e p o l e pine No. 3 p o w e r - l o s s m e t e r measurements. Df  Mean s q u a r e s  4 14 2 8 28 1 2 143  3.58 3.39 3452.90 3.85 2.85 9.84 3.35 0.37  Test term  F  +  Sample/H  1.06 9.09 9251.17 10.31 7.63 26.36 8.96  Common s l o p e f o r a d j u s t m e n t = 24.33 * i n d i c a t e s i g n i f i c a n c e a t 0,05 l e v e l , ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t , +  D e s i g n a t e term f o r F - t e s t .  B l a n k i n d i c a t e s t h e t e s t term i s ''Error' , 1  Covariate  Significance N.S.  ** ** ** ** ** **  Tab!ell.  A n a l y s i s o f v a r i a n c e t a b l e f o r l o d g e p o l e p i n e No. 4 p o w e r - l o s s m e t e r measurements.  Source o f v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC Radial vs. tangential D i r e c t i o n x MC Error Total Studentized Height Frequencies Means  Df  Mean s q u a r e s  Test term  4 14 2 8 28 1 2 150 209  21.44 4.75 4572.10 5.71 2.83 9.18 3.53 0.48  Sample/H  F  +  4.51 9.92 9544.09 11.93 5.91 19.16 7.37  Significance * ** **. ** ** ** **  Newman-Keul's t e s t , l e v e l o f s i g n i f i c a n c e = 0.05 5  30 27.23  T  54 26.90  3  42 26.04  2 48 25.73  4  36 25.52  Means u n d e r l i n e d by t h e same l i n e are n o t s i g n i f i c a n t l y d i f f e r e n t from each o t h e r . * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t . Designiate term f o r F - t e s t .  Blank i n d i c a t e s t h e t e s t term i s " E r r o r " .  T a b l e 12. A n a l y s i s o f c o v a r i a n c e is specific gravity. Source of v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l vs_. t a n g e n t i a l D i r e c t i o n x MC Error  f o r l o d g e p o l e p i n e No. 4 p o w e r - l o s s m e t e r measurements. Df  Mean s q u a r e s  4 14 2 8 28 1 2 149  7.96 5.93 4577.10 5.89 2.76 9.18 3.53 0.33  Test t e r m Sample/H  F  +  1.34 17.73 13684.56 17.61 8.26 27.44 10.56  Common s l o p e f o r a d j u s t m e n t = 36.96 * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t +  D e s i g n i a t e term f o r F - t e s t .  B l a n k i n d i c a t e s t h e t e s t term i s " E r r o r " .  Covariate  . Significance N.S.  ** ** ** ** ** **  T a b l e 13. A n a l y s i s o f v a r i a n c e t a b l e f o r l o d g e p o l e ments. Source o f v a r i a t i o n Sample M o i s t u r e c o n t e n t (MC) Sample x MC R a d i a l y_s_. t a n g e n t i a l D i r e c t i o n x MC Error Total  Df 4 2 8 1 2 30 47  Mean s q u a r e s  p i n e r e a c t i o n wood p o w e r - l o s s meter measureTest term  +  6.09 755.10 1.49 2.48 0.41 4.58  * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t . +  D e s i g n a t e term f o r F - t e s t .  B l a n k i n d i c a t e s t h e t e s t term i s ''Error".  F 1.33 164.84 0.32 0.54 0.09  Significance N.S.  **  N.S. N.S. N.S.  T a b l e 14.  A n a l y s i s o f v a r i a n c e t a b l e f o r w h i t e s p r u c e p o w e r - l o s s meter measurements.  Source o f v a r a i t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l y_s_. t a n g e n t i a l D i r e c t i o n x MC Error Total T a b l e 15. A n a l y s i s o f c o v a r i a n c e specific gravity. Source o f v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC Radial vs. tangential D i r e c t i o n x MC Error  Df  Mean s q u a r e s  T e s t term  4 16 2 8 32 1 2 180 245  30.54 10.64 3232.70 3.64 2.25 25.63 4.53 0.29  Sample/H  F 2.87 36.70 11146.21 12.56 7.76 88.36 15.60  N.S  ** ** ** ** ** **  f o r w h i t e s p r u c e p o w e r - l o s s meter measurements. C o v a r i a t e i s Df  Mean squares  4 16 2 8 32 1 2 179  16.51 6.64 3230.10 3.61 2.25 25.63 4.53 0.29  Test term Sample/H  F  +  2.49 22.88 11126.53 12.43 7.73 88.28 15.59  Common s l o p e f o r a d j u s t m e n t = -3.29 * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t . D e s i g n a t e term f o r F - t e s t .  Significance  B l a n k i n d i c a t e s t h e t e s t term i s " E r r o r " .  Significance N.S.  ** ** ** ** ** **  T a b l e 16.  Analysis of variance  t a b l e f o r D o u g l a s - f i r p o w e r - l o s s m e t e r measurements.  Source o f v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC R a d i a l vs_. t a n g e n t i a l D i r e c t i o n x MC Error Total T a b l e 17. A n a l y s i s o f c o v a r i a n c e specific gravity. Source of v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) . H e i g h t x MC S/H x MC Radial vs. tangential D i r e c t i o n x MC Error Common s l o p e f o r a d j u s t m e n t =  Df  Mean s q u a r e s  4 14 2 8 28 1 2 156 215  29.97 45.07 1310.00 2.47 9.61 10.89 2.93 0.60  T e s t term  F  Sample/H  0.67 74.75 2172.79 4.10 15.94 18.06 2.43  f o r D o u g l a s - f i r p o w e r - l o s s meter measurements. Df  Mean squares  4 14 2 8 28 1 2 155  1.08 16.65 1291.00 2.79 9.26 10.89 1.46 0.56  Test term  +  Sample/H >  51.98  * i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l N.S. i n d i c a t e n o t s i g n i f i c a n t . +  D e s i g n i a t e term f o r F - t e s t .  B l a n k i n d i c a t e s t h e t e s t term i s " E r r o r " ,  F 0.06 29.87 2316.06 5.01 16.62 19.54 2.62  Significance N.S.  ** ** ** ** **  N.S.  Covariate i s Significance N.S.  ** ** ** ** **N.S.  T a b l e 18.  A n a l y s i s o f v a r i a n c e t a b l e f o r s u b a l p i n e f i r p o w e r - l o s s meter measurements.  Source o f v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC Radial vs. tangential D i r e c t i o n x MC Error Total T a b l e 19. A n a l y s i s o f c o v a r i a n c e specific gravity. Source o f v a r i a t i o n Between h e i g h t Sample w i t h i n h e i g h t (S/H) M o i s t u r e c o n t e n t (MC) H e i g h t x MC S/H x MC Radial vs. tangential D i r e c t i o n x MC Error  Df  Mean squares  4 11 2 8 22 1 2 129 179  14.20 5.23 2770.50 2.06 5.41 8.45 0.33 0.41  Test term  F  +  Sample/H  2.71 12.74 6747.96 5.01 13.19 20.58 0.81  Df  Mean s q u a r e s  4 11 2 8 22 1 2 128  1.83 4.21 2774.40 2.15 5.57 8.45 0.33 0.32  Test term Sample/H  F  +  0.44 13.07 8619.85 6.69 17.31 26.25 1.03  • i n d i c a t e s i g n i f i c a n c e a t 0.05 l e v e l . ** i n d i c a t e s i g n i f i c a n c e a t 0.01 l e v e l . N.S. i n d i c a t e n o t s i g n i f i c a n t . D e s i g n a t e term f o r F - t e s t .  N.S.  ** ** ** ** **N.S.  f o r s u b a l p i n e f i r p o w e r - l o s s meter measurements. C o v a r i a t e i s  Common s l o p e f o r a d j u s t m e n t = 43.53  +  Significance  B l a n k i n d i c a t e s t h e t e s t term i s " E r r o r " .  Significance N.S.  ** ** ** ** **N.S.  75  Comparison o f power-loa3 moiaturo meter (Moisture Regiostor Model L) c o r r e c t i o n tables f o r lodgepole pine pooled data. Manuf a c t u r e r supplied data and the table prepared by Bramhall and Salamon ( 11 ) are given f o r comparison. Underlined data are extrapolated.  Table 20.  LpdTepole  Met er reading  Radial  G  face:  0.36 0.39 0.42 0.45  Content  Tanrrential f a c e s 0.36 0.39 0 . 4 2  0.45  Hanuf act.  6.6  15  16 17 18 19 20 21 22 23  7.7 8.8 9.9 10.9 11.8 12.7  13.5  14.2 15.0 15.6 16.2 16.8 17.3 17.8 18.4  24  25 26 27  28 29 30  • •••  31 32 33 34  *  nine  r!oi3ture  19.2 ••#•  19.9 o  Temperature used i s 20 C.  •B & S* 5.5 6.7 7.8 8.9 9.9 10.9 11.8 12.7 13.7 14.7 15.5 16.3 16.9 17.5 18.1 16.7 19.2 19.7 20.1 20.6  76  T a b l e 21. Comparison of power-loss moisture motor "(Moisture Resioster Model L) correction tables for white spruce data. Manufacturer supplied table and the table prepared by Bramhall and Salamon ( i f ) are given for comparison. Underlined data are extrapolated.  White  Meter reading ui  16 17  18 19 20  21 22 23 24 25 26 27  28  29 3° 31 32  33  34 *  K a d i a l laces u . i U 0.32 0.34 0.36  5*6 10.2 7.9 4^4 2^3 11.7 9.6 2 s l 5 i l 12.9 11.1 9.0 7.2 14»1 12.5 10.6 8.3 • 15.1 13.6 12.0 10.0 16.1 14.7 13.2 11.5 17.1 15.8 14.3 12.8 17.9 16.7 15.4 13.9 18.8 17.6 I6.4 15.0 19.6 18.5 17.3 16.0 20.4 19.3 18.2 16.9 21.1 20.1 19.0 17.8 21.8 20.8 19.8 18.7 22,5 21.6 20.6 19.5 .23.2 2 2 . 3 21.3 20.3 23.9 2 3 . 0 22.0 21.0 24.5 23.6 2 2 . 7 21.7 25.1 2 A . 3 2 3 . 4 22.5 2 5 . 8 2 4 . 9 2 4 . 0 23.1  o Temperature used i s 20 C.  spruce Moisture content Tangential f n r p o 0.30 0.32 0.34 0.36  8.0 5.1 3_.jL .... 9.7 7.4 6Jp_ 4^6 9.1 7.9 12.3 10.6 8.6 "679 13.4 11.9 10.1 8.0 14.5 13.0 11.5 9.6 15.4 14.1 12.7 11.0 16.3 15.1 13.8 12.3 17.2 16.0 14.8 13.4 18.0 I6.9 15.7 14.4 18.8 17.7 16.6 15.4  19.6 18.5 17.5 16.3 20.3 19.3 18.3 17.2 21.0 20.0 19.0 18.0 21.7 20.7 19.8 18.8 2 2 . 3 2 1 . 4 20.5 19-5 23.0 22.1 21.2 20.3 23T6" 2 2 . 7 21.9 21.0 24.2 2 3 . 4 .22.5 21.6 2475* 2 4 . 0 2 3 . 2 22.3  "  Manu— fact. 5.4  B & S*  4.4  6.5  5.5  7.5 8.4 9.4 10.3  6.5 7.5  11.1 11.9  12.5 13.2 13.9 14.4 14.9 I5.4  16.0  16.6-  ....  17.2  ....  18.1  8.5  9.4  10.3  11.2 12.1 12.9  13.7 14.4 15.0 15.6 16.2 16.9 17.3 17.8 18.3 18.8  77 Table 2 2 . Comparison o f power-loss moisture meter (Moisture R o g i - s t e r Model L) c o r r e c t i o n t a b l e s f o r D o u g l a s - f i r .data. Manufacturer s u p p l i e d t a b l e and the t a b l e prepared by Bramhall and Salamon I 11 ; are g i v e n f o r comparison. Underlined data a r e e x t r a p o l a t o d  —  Dou,crla3-fir  Meter reading  R a d i a l faces G: 0.40 0.43 0.4o 0.49  "'" ~"  Moisture content Tangential faces 0.40 0.43 0.46 0.49  15 16  -  17  3.8  18 19  20 21  22 23  24 25 26 27 28 2  9  3° 31 32 33 3 4  t  2.2  6.1 J>i2 4-2 0T2 2ti i i i 10.1 8.8 7.9 11.2 9.2 8.2 13.1 10.8 9.6 14.7 11.8 10.5 16.1 13.6 11.5 17.4 15.1 12.4 18.6 I 6 . 5 14.I 19.8 17.8 15.6 20.9 19.0 16.9 21.9 20.1 18.2 22.9 21.2 19.4 23.8 22.2 20.5 24.7 23.2 21.5 25.6 2 4 . 1 22.5  4*1 2^8 ^5  6^3 7.7  8.9  9.9  10.6 10.9 11.6 13.0 14.6 16.0 17.3  18.6 19.7  20.8  2^25^23^-21^8 Temperature used i s 20°C.  HgMSllS  5.5 6.3 7.0 ~  2.5 .... ....  ^_3 4^2 7.9 7^0 6^2 9.7 8.0 7-3 10.8 8.7 8.0 12.6 10.3 8.9 14.1 11.3 10.1 15.5 13.0 10.9 16.8 14-5 11.8 18.0 15.9 13.4 19.1 17.1 14.9 20.1 18.3 16.2 21.1 19.4 17.4 22,1 20.4 18.6 23.0 21.4 19.7 23.9 22.3 20.7 2 4 . 7 2 3 . 3 21.7 6^2  Manu—. fact.  2^2 5^4  bTl  7.5 8.6 9.7 10.1 10.4 11.5 12.2  13.8  15.2  16.5 17.8  18.9 19.9  21»0  P _/  7.7  8.4 9.1 9.7  10.3 10.9 11.5 12.1 12.7  13.2 13.7 14.4  15.1  B & 5*  4.7 . / • v> 5.6 6.3 7.1  7.8 8.5  9.1 9.8 10.5 11.3 12.0 12.8  13.3 13.9  14.7 15.5  16.1 16.0 17^2  16.8 18^2  78  Table 23. Corapariaon o f power-loss moisture meter (Moisture R e g i s t o r Model L ) c o r r e c t i o n t a b l e s f o r subalpine f i r d a t a . Manufacturer s u p p l i e d t a b l e and the t a b l e prepared by Bramhall and Salamon ( 11 ) a r e g i v e n f o r comparison. Underlined data a r e extrapolated.,  Meter rPirtinxr  •  J  10 1 6  17 18 19  20 21 22 23  24 25 26 27  28 29  30 31 32 33 34  Subaloino f i r Moisture C o n t e n t Radial faces Tangential faces G i 0.35 0.37 0-39 0.41 0.35 0.37 0.39 0.41  1*1  3^4  111 3.7 7.4 9.0  10.4  13 8.1 9.6  11.6 10.9 12.7 12.0 13,7 13.1 14.6 14.1  5_^0 3_a 7.1 6^0 "BTB" 7.9 10.2 9.4 11.4 10.7 1 2 . 5 11.9' 13.5 13.0 1 4 . 5 13.9  1 5 . 5 15.0 16.3 15.8 1 5 . 3 14.8 17.1 16.6 16.2 15.7 17.8 17.4 17.0 1 6 . 5  18.6 18.117.7 17.3 19.3 18.9 18.5 18.0 19.9 19.5 19.2 18.8 20.6 20.2 19.8 19.4 21.2 20.8 2 0 . 5 20.1 21.8 2 1 . 5 21.1 20.8 22.4 22.1 21.7 21.4  4^1 6^8  8.5  2^5_ i t l .... ^6 ^2 lv9 7.6 6.6  -9.9 9.1 0T3 7.4 11.1 10.4 9.7 9.0 12.2 11.6 11.0 10.3  13.2 12.7 12.1 1 1 . 5 14.2 13.7 13.1 12.6  15.0 14.6 14.I 13.6 1 5 . 9 15.4 15.0-14.5 16.7 16.2 15.8 15.3 17.4 17.0 16.6 16.2  18.2 17.8 17.4 16.9 18.8 18.5 18.1 17.7 19.5 19.2 18.8 18.4 20.2 19.8 19.5 19.1 20.8 2 0 . 5 20.1 19.8 21.4 21.1 2O.7.2O.4 22.0 21.7 21.4 21.0  ., Manu-* _ , fact.  7.2 8.1 9.0 9.9  2.2 3.3  4.5 5.7 6.8  10.7 11.4 12.1 12.8 13.5  7.9 8.9 9.9 11.1  14.1  12.2  14.7 15.2 15.7  14.3  16.2 16.7  17.2 .... 17.9 .... 18.6.  * Data f o r s u b a l p i n e f i r (Abies l a s i o c a r p a (Hook.) N u t t . ) i s not a v a i l a b l e . Readings f o r "white f i r " a r e used. ** Temperature used i s 20°C.  0  13.2  15.0  15.7 16.5 17.4 18.0 18.7 19.3  19.8  ^  79 Table 24. Pig  L i s t of regression equations.  6. Radial faces Lodgepole pine 1-4 Y=» 19.12 - O.448 MC + O.O557 MC  ,SE  E  1.52)  E  1.06)  E  1.68)  Lodgepole pine No. 4 Y » 20.45 - 0.627 MC + 0.0662 MC' [SE White spruce Y « 15.76 - 0.174 MC + 0.0372 MC  [SE  Douglas-fir Y B 21.44 - 0.124 MC + 0.0270 MC  2.13)  Subalpine f i r Y = 14.26 + 0.273 MC + 0.0284 MC' .SEg  1.26)  Tangential faces Lodgepole pine 1-4 Y = 19.52 - 0.507 MC + 0.0597 MC  [SE  E  1.49)  T - 20.67 - 0.681 MC + 0.0706 MC 2 [3E  E  1.02)  Y = 15.86 - 0.175 MC + 0.0396 MC' 'SEE  1.68)  Lodgepole pine No. 4 White spruce Douglas-fir  Y = 22.46 - 0.271 MC + 0.0337 MC  SEE  ;  2.26)  Subalpine f i r Y = 14.27 + 0.313 MC + 0.0278 MC'  SEE  1.16)  SEE  0.66)  SE  0.86)  Pig 7. Radial faces Lodgepole pine No. Y = 20.32 - O.848 MC + 0.0691 MC' Lodgepole pine No. 2 Y » 18.68 - 0.502 MC + 0.0571 MC' Lodgepole pine No.  'E  3  Y » 17.63 + 0.063 MC + 0.0350 MC*  SEE  1.02)  ,SE  1.06)  Lodgepole pine No. 4 Y B 20.45 - 0.627 MC + 0.0662 MC* (Continue next page)  E  80  Table 24. Continued Lodgepole pine reaction wood Y » 19.12 + 0.237 MC + 0.0295 MO  ( S E j . — 1.86)  2  Tangential faces Lodgepole pine No. 1 Y = 20.60 - 0.853 MC + 0.0706 .MC (SE = 0.73) 2  E  Lodgepole pine No. 2 Y a 19.41 - 0.604 MC + 0.0625 MC ( S E = 0.82) 2  E  Lodgepole pine No. 3 Y = 18.10 - 0.024 MC + 0.0403 MC (SE «= 1.02) 2  E  Lodgepole pine No. 4 Y = 20.67 - 0.681 MC + 0.0706 MC (SEj;^ 1.02) 2  Lodgepole pine reaction wood Y = 18.73 + 0.311 MC + 0.0286 MC (SE = 1.74) 2  E  Pig 8. Radial faces Lodgepole pine 1-4 Y«16.31 + 0.0401. MC  2  ( S E = 1.55) E  Lodgepole pine No. 4 Y = 16.58 + 0.0442 MC  2  ( S E = 1.13) E  White spruce Y = 14.64 + 0.0313 MC Douglas-fir Y = 20.65 + 0.0228 MC  2  (SE = 1.68) E  2  ( S E = 2.26) E  Subalpine f i r Y = 15.94 + 0.0380 MC  2  ( S E = 1.27) E  Tangential faces Lodgepole pine 1-4 Y = 16.34 + 0.0421 MC  2  ( S E » 1.52) E  Lodgepole pine No. 4 Y = 16.46 + O.O467 MC  2  (SE =. 1.11) E  White spruce Y-14.73 + 0.0337 MC  2  (SE = 1.67) E  Douglas-fir Y-20.75 + 0.0243 MC  2  ( S E » 2.26) W  Table 24. Continued. Subalpine f i r Y = 16.20 + 0.0388 MC2 ( S E = I.17) E  Pig 9 . • Radial faces Lodgepole pine No. 1 Y = 14.99 + 0.0399 MC2 ( S E = 0.87) E  Lodgepole pine No. 2 Y « 15.54  + 0.0396 MC2  ( S E » 0.92) E  Lodgepole pine No. 3 Y « 18.03 + 0.0371 MC2  ( S E = 1.02) E  Lodgepole pine No. 4 Y«l  .58 + 0.0442 MC2 ( S E = 1.13) E  Tangential faces lodgepole pine No. 1 Y = 15.23  + 0.0412 MC2  ( S E = 0.93) E  Lodgepole pine No. 2 Y«= 15.64 + 0.0414 MC2  ( S E = 0.91) E  Lodgepole pine No. 3 Y » 17.95  + 0.0395 MC2  ( S E = 1.01) E  Lodgepole pine No. 4 Y = 16.46 + O.O467 MC2 ( S E = 1.11) E  Pig 10. Radial faces Lodgepole pine 1-4 Y = 16.31 + 0.0401 MC2  (SE  = 1.55)  E  Lodgepole pine reaction wood Ye 20.63 + 0.0376 MC2  ( S E » 1.83) E  Tangential faces Lodgepole pine 1-4 Y = 16.34  + 0.0421 MO2 (SE »= 1.52) E  Lodgepole pine reaction wood Y » 20.72 + 0.0393 MC2  ( S E = 1.71) E  82  Fig  1. Schematic diagram of sample preparation and scheme of measurements.  S A M P L E S L A B CUTTING SAMPLE oAMrLfc. TREE  HEIGHT L E V E L SEGMENT 3cm  l 45cnr  1 SAMPLE STRIP  SPECIMEN PIECES am  • I  i  I  t  I  i i  '  ] ,  40 cm i  '  • i  ,10cm  i-t  LUil  PITH HEARTWOOD SAPWOOD 1  TT .  5  2.5 cm  RESISTANCE METER M E A S U R E M E N T S (RADIAL AND TANGENTIAL F A C E S )  .A  R A D I A L FACE  TANGENTIAL FACE  POWER-LOSS METER  MEASUREMENTS  83  F i g 2. S p e c i f i c g r a v i t y ( o v e n - d r y w e i g h t a n d " g r e e n " v o l u m e ) v a r i a t i o n s among s p e i c e s . L o d g e p o l e p i n e No. 4, w h i t e s p r u c e , D o u g l a s - f i r and s u b a l p i n e f i r sample s p e c i f i c g r a v i t i e s a t 5 h e i g h t l e v e l s and r a d i a l s e r i e s a r e p r e s e n t e d . Right-most p o i n t s a t each h e i g h t l e v e l a r e t h e sapwood s a m p l e s . Number o f o b s e r v a t i o n i s e i g h t f o r e a c h p o i n t . G 1 .551  <L  I  PITH  '  X A  •••••  4  3  b  PERIPHERY  •LEGEND-  Lodgepole pine  •  Douglas-fir  Wlilto spruco  +  Subolplno fir  Fig  •84  3. S p e c i f i c g r a v i t y ( o v e n - d r y w e i g h t and " g r e e n " v o l u m e ) v a r i a t i o n s among l o d g e p o l e p i n e t r e e s ( i n c l u d i n g c o m p r e s s i o n wood) a t 5 h e i g h t l e v e l s and r a d i a l s e r i e s a r e p r e s e n t e d . R i g h t - m o s t p o i n t s a t e a c h h e i g h t l e v e l a r e t h e sapwood s a m p l e s . Number o f o b s e r v a t i o n i s e i g h t f o r each p o i n t . G I  -60i .50  .30 *  ;  I p  ™  2  3  4 5 PERIPHERY  • LEGEND• Lodgepole pine no.I  *• •  Lodgepole pine no. 3 XLodgepole pine reactlonwood  Lodgepole pine no.2 Lodgepole pine no.4  Fig 4. Resistance moisture meter measurements yj_ moisture contents (oven-dry basis) for between species comparison as lodgepole pine No. 4, white spruce, Douglas-fir and subalpine f i r . (Solid lines represent heartwood samples and dashed lines represent sapwood samples. Symbols on lines serve to distinguish between lines and are not data points.)  32 LEGEND: 28  Lodgepole pine no.4  x  *  White spruce .  •  pouglas-ffr  + .."... .Subalpine fir  5  l 0  8  12  16  20 24 28 MOISTURE CONTENT (%)  32  36  F i g 5. R e s i s t a n c e m o i s t u r e m e t e r measurements on l o d g e p o l e p i n e samples v s . m o i s t u r e c o n t e n t s (ovendry b a s i s ) . ( S o l i d l i n e s r e p r e s e n t heartwood samples, and dashed l i n e s r e p r e s e n t sapwood samples. Symbols on l i n e s s e r v e t o d i s t i n g u i s h between l i n e s and a r e not d a t a p o i n t s . )  LEGEND: Lodgepole pine I Lodgepole pine 2 Lodgepole pine 3 . Lodgepole pine 4  OH?  |2  '  16  20 24 ' 2§ 32 MOISTURE CONTENT (%)  36  6  G r a p h showing t h e r e l a t i o n s h i p between power-loss meter r e a d i n g s and m o i s t u r e c o n t e n t s ( o v e n - d r y b a s i s ) o f l o d g e p o l e p i n e p o o l e d ( L l - 4 ) , l o d g e p o l e p i n e No. 4 ( L 4), w h i t e s p r u c e (W.S.), D o u g l a s - f i r (D.F.) and s u b a l p i n e f i r ( A . F . ) ; (Symbols on r e g r e s s i o n l i n e s s e r v e t o d i s t i n g u i s h between l i n e s am are n o t data p o i n t s . ) ,  BETVEEN SPECIES (RADIAL)  L.P.1-4.  L.P.#4.  BETWEEN SPECIES ' (TANGENTIAL)  V.S.. D.F.. fl.F.  o  LI-4RXX2=.9397  L!-4RXX2=.947<  fi-  L4  L4  RXX2=.9747  L.P.1-4.  L.P.*4.  V . S . . D . F . . fl.F.  :  RXX2=.9788  W.S. RXX2=.89«8  W.S RXX2=.9085  D.F. RXX2=.728G  D.F. RXX2=.7323  A.F. RXX2=.9S17  A.F.  RXX2=.9607  CO CO  go  LUo.  lu'  Lu' I— LU So  LEGEND: • Lodgepole ptne 1-4 x .). Lodgepole pine 4 0 . . . . . . . - W h i t e spruce * Douglas'-fir Subolplhe fir  R#*2 = R* o ui' CO  o o"  0.0  I  8.0  12.0  16.0  MOISTURE CONTENT (J)  20.0  24.0  0.0  1  4.0  I 8.0  1  12.0  _  1—  16.0  MOISTURE CONTENT (J)  20.0  24.0  F i g 7. Graph showing t h e r e l a t i o n s h i p between power-loss meter r e a d i n g s and m o i s t u r e c o n t e n t ( o v e n - d r y b a s i s ) o f l o d g e p o l e p i n e No. 1 ( L I ) , l o d g e p o l e p i n e No. 2 ( L 2 ) , l o d g e p o l e pine No. 3 ( L 3 ) , l o d g e p o l e p i n e No. 4 ( L 4) and l o d g e p o l e p i n e compression wood (LRW). (Symbols on l i n e s a r e n o t d a t a p o i n t s . ) BETWEEN L.P.«1. *2. #3. «4. L.R.V.  BETWEEN L.P.#1. #2. #3. #4. L.R.V.  (RADIAL)'  (TANGENTIAL)  L I RXX2=.988S L 2 RXX2=.9789 L 3 RXX2=.9693 L 4 RXX2=.9747 LRWRXX2=.9106  L I RXX2=.9867 L 2 RXX2=.9824 L 3 RXX2=.9730 L 4 RXX2=.9788 LRW RXX2=.9273  tn. co  cn  tn. CM  cn _ i—t  s-  UJa. C_OJ  LY. UJ t— txJ _ a  LEGEND: 6  Lodgepole pine I  ^ _|  s...... - Lodgepole pine 2 £ Lodgepole pine 3 *• Lodgepole pi'ne 4I Lodgepole pine reaction wood.  o  in  0.0  A.  a  —i 8.0  MOISTURE  12.0  CONTENT  i— .6.0  20.0  ~1  24.0  0.0  -I— 4.0  8.0  12.0  MOISTURE CONTENT  15.0  it)  24.  20.0 oo  F i g 8. Graph showing t h e r e l a t i o n s h i p between p o w e r - l o s s meter reading;, and m o i s t u r e c o n t e n t s q u a r e d (oven-dry b a s i s ) o f l o d g e p o l e p i n e No. 4 (L 4 ) , l o d g e p o l e p i n e p o o l e d ( L l - 4 ) , w h i t e s p r u c e (W.S.)» D o u g l a s - f i r (D.F.) and s u b a l p i n e f i r ( A . F . ) . (Symbols on r e g r e s s i o n l i n e s s e r v e t o d i s t i n g u i s h between l i n e s and a r e not d a t a p o i n t s . ) L.P.C1-4). L.P.«4.  L.P.U-4) .' L.P. #4. V.S.. D.F.. fl.F. (TflNGENTIf  V.S.. D.F..fl.F.(RRDIRL) o  Lf-4 RXX2=.9373  o  L4  KH  RXX2=.9705 RKX2=.7282  A.F.  RX*2=.9507  L4 W.S.  W.S. RX*2=.8942 D.F.  Ll-4  D.F.  a  A.F.  in.  in. ra  CO CD  go. LUo.  Ol UJ  LEGEND:  in o  I—  *>  Lodgepole pine 1-4  x  Lodgepole pine 4  °  White spruce  *S  Douglas-fir  o  Subalpine fir  UJ  o  o  in  in  10  o t  0.0  -1 £0.0  1 160.0  15  1 240.0  20 1 320.0  MOISTURE CONTENT SQUARED '  400.0  MC(%) 1 430.0  a o  10 ~i— 80.0 1  0.0  1  1S0.0  15 '-i 240.0  1  320.0  MOIJTURE CONTENT SQUARED •  :  20  MC(%  I  400.0  430.1  co 10  F i g 9. Graph showing the r e g r e s s i o n o f l o d g e p o l e p i n e t r e e power-loss meter r e a d i n g s on m o i s t u r e c o n t e n t squared (oven^-dry b a s i s ) . These two v a r i a b l e s e x h i b i t q u a d r a t i c r e l a t i o n s h i p s . (Symbols on r e g r e s s i o n l i n e s s e r v e t o d i s t i n g u i s h between l i n e s and a r e n o t data p o i n t s . ) LODGEPOLE PINE #1. #2. #3. #4 LI L2 L3 L4  LODGEPOLE PINE #1. #2. #3. #4  (RRDIRL)  RXX2=.9798 RKX2=.9758 RXX2=.9693 RXX2=.9705  (TRNGENTIRU  in. rn  a . cn  o  CO CO _  .  in. cv  So U-lo.  LEGEND: ^ o Lodgepole pine J _ t— s Lodgepole pine 2 W fi Lodgepole pine 3 i n . X Lodgepole pine 4 Q  RXX2 = R2 a a .  in 7 0.0  10 1 80.0  f5 1 160.0  "-i 240.0  20 !  — —I 1  320.0  MOISTURE CONTENT SQURRED  1 400.0  MC (%)  |  480.0  7  °.  o  _ 0.0  10 I 80.0  [5 | 160.0  •| 240.0  I 320.0  MOISTURE CONTENT SQURRED '"  20 —1  400.0  MC (%)  _ o  430.0  F i g 10. Graph showing t h e r e l a t i o n s h i p between p o w e r - l o s s meter r e a d i n g s and m o i s t u r e c o n t e n t squared ( o v e n - d r y b a s i s ) o f l o d g e p o l e p i n e compression wood {LRW) and r e g u l a r woods (L 1 - 4 ) . (Symbols o n r e g r e s s i o n l i n e s s e r v e to. d i s t i n g u i s h between l i n e s and a r e n o t data p o i n t s . ) 9-1  L. P. REACTION VOOD. LODGEPOLE P. 1-4 POOLED (RADIAL) Ll-4  in.  LRW  L. P. REACTION VOOD. LODGEPOLE P. 1-4 POOLED (TANGENTIAL) L l - 4 RXX2=.9262 LRW RXX2=.944S  a-4  in.  CO CD  go  L U o .  C£ LU  I—  LU  tn. LEGEND: C•••  , Lodgepole pine 1-4 Lodgepole pine " reaction wood m  a o.  a  in"  1.5  1.0 0.0  60.0  150.0  240.0  20 320.0  MOISTURE CONTENT SQUARED .  400.0  MC(%)  480.0  1  0.0  !  1.0  80.0  ,  160.0  15 , 243.0  ,  320.0  .MOISTURE CONTENT SQUARED  20__ 4C0.0  430  92  Appendix I .  C h a r a c t e r i s t i c s o f sample t r e e stems showing t o t a l stem l e n g t h , diameter and segments a c c o r d i n g to height l e v e l (measured i n meters from stem base).  Stem  Length,  Height L e v e l ,  m  m  Diameter, cm. tease)  1  2'  3  4  Lodgepole pine No. 1  12.45  36.9x 36.3  0.70  4.67  7.42  10.05  Lodgepole pine No. 2  16.47  35-6x 36.3  0.84  4.05  7.71  9.85  14.69  Lodgepole pine No. 3  14.84  33.1 x 34-4  1.15  5.32  7.56  10.00  13.77  Lodgepole pine No. 4  16.12  35.6x 35-6  1.45  5.16  7.25  10.16  13.34  31.8z 36.9  0.95  —  —  Lodgepole pine HW  —  —  5 —  White spruce  13.47  38.2z 38.2  0.89  4.84  7.06  9.75  12.03  Douglasfir  14.74  38.2x 39.5  1.06  4.9?  7.55  10.14  13.11  Subalpine fir  14.95  33.1x 32.8  1.21  5.04  7.40  10.08  13.24  Appendix II. Growth zone numbora i n the c e n t e r of each apecimcn orosa o e c t i o n . R a d i a l s e r i e s No. 1 rcprenenta corewood, No. 2 to 4 represent heartwood and No. 5 r e p r e s e n t s sapwood wood zones.  Sample Tree:  Height L e v e l  Lodgooole pine No. 1  1 2 3 4  Lodgepole No. 2  pine  l 2 3  4 5 Lodgepole No. 3  pine  •  1 2  Lodgepole No.  4  pine  1  2  3  4  .5  8 12  27  45  75  90  7  10 9 7 13 7  11 9. 13  15  9 8 7 8 12 13 8  11  7 9  2  4 . 5  (oontinue next page)  —  18  33  —  24  48  70  24 27  30  56 43  25  46 23 37 18  ,  +  40  80  —  33  ——  —  —  —  28 45  51 68 44  73 ——  33  —  —  —  __.  —  15  —  —,...  9 7 8 10 8 13 9  23 21 26  45 34 47 38  7  27  6  16  25  — —  —  5  100 +  —  _  35  15  64  —  ——.  35 35 30  65  +  27  22 25  69  72  95  —-  .  90*  —  ——  25  +  61 52  24  5  1  44  —  13  1  —  48 44  5  7  70  28  4  3  Lodgepole p i n e reactionwood  25  9 11  5  51 52  30 30  36 20 31 36  3  No. growth zone  Radial scries  7  0  65  74 65 60  48  45  100 + 100 + 74 80 62 67 62  50 43 37  •  —  —  80 85 74 79 80 76 67 70 51 60  27  40  68  44  —  54 — — —  ——  — —  ——  55  94 Appendix II.(continued.)  Radial s e r i e s Sample trees White  spruce  Height l e v e l s 1 2 3 4 5  Douglas-fir  1  2 3 4 5  Subalpine f i r  1 2 3 4 5  8 8 6 10 6 6 4 6 10 9  21  10 9 12 10 10 11 8 8 I'll  22 24 24 27 29 35 24 33 23 31  16 14 16 13 17 19 14 15 13 14  38 32 48 38 45 44 39 41  18  16 18 14 15 12 14 22 22  31  28 26  31 27 29 24 25 —  43 39 37 . —  — — — — —  —  36 43 45 47  55 — —  — —  38  —  — —  —  —  —  66 63  —  —  -—  64 —  —  —  —  —•  —  —  —-  —  —  —  —  —  55 54 50 53 46 44 41 45 41 43 74 68 65 63 54 55 49 46 38 44 90 100 80 . 88 72 74 55 60 43 45  + +  95  Appendix III. C i r c u i t r y o f t h e p o w e r - l o s s m o i s t u r e m e t e r , ( M o i s t u r e R e g i s t e r ) . Where M i s t h e m e t e r , V i s a vacuum t u b e and X is t h e s a m p l i n g e l e c t r o d e s . A d o p t e d f r o m Uyemura (88).  \  9.6. Appendix IV. R e s i s t a n c e moisture meter (Delmhorst RC—IB) measurements (MT) on wood samples from t r e e s o f the study compared t o oven-dry (OD) c a l c u l a t i o n s ; i n c l u d i n g nominal moisture l e v e l (N MC), at stem h e i g h t s ( S t . ) and f o r two r a d i a l r e p l i c a t i o n s (1-4 heartwood, 5 sapwood). Observations are 16 f o r each r e a d i n g at 19 and 12^ nominal moisture l e v e l , and 8 f o r each r e a d i n g at "green" c o n d i t i o n . Lodgepole pine 1 Ht. N'MC  Moisture Content Measurements  Repl. OD  G 19 12  G 19 12  G 19 12  G 19 12  1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2  33.0  31.8 20.7 21.1 13.6  13.8  32^8 31.8 20.5 20.6  13.5 13.5 32.3 32.2  21.4  MT  24.7  23.6 16.2 17.0 10.7 li.i 23.6 23.3 16.0 16.1 10.6 10.7  23.8  24.4 17.0  OD  MT  31.6 30.9  22.3 22.7 16.2  20.5 20.8 13.6  13.5 29.7 30.2 19.8  16.5 10.6 10.7 21.3 22.0  13.3  15.7 15.8 10.4  13.5  10.7  20.4 31.2  24.0  30.5  23.1 16.6  20.6  16.8 L'19.8. 16.2 13.9 10.8 13.2 10.4 21.2  13.5  10.7  29.3  22.6  27.4 21.1  20.9 16.5 20.8 16.4  13.6 13.2  (Continue next page)  10.7 10.6  13.1 29.0 27.5 20.9 20.8 13.2 13.6  10.4 22.5 20.9 16.5 16.7  OD  MT  29.4 21.5 30.5 22.1  20.2 20.3 13.3 13.4  15.9 15.8  30.2 28.3 20.4 19.7 13.6 13.0  22.0 21.0  30.8 29.6 20.7 20.3 13.2  10.2 10.4  30 28 19 19 13 13  MT  0 21 20 15 15 10 10  OD  8 7 1 6  1 1  102.3  MT  35.2  84.5 31.6 20.7 16.6 20.5 l6.5  13.7 13.7  10.8  10.7  95-9 34.1 67.6 29.5 20.9 15.9 20.7 15-9 13.8 11.2 13.6 10.9 86.7 32.5 79.1 31.2  15-6 15.4 10.3 10.1 23.2 21.8 16.2  13.5  10.4 10.7  21.2 16.8 20.8 16.5 13.8 11.0 13.7 11.1  28.6  21.7  70.7  29.5  20.1  15.8  20.9  16.7 10.9 11.3  • •••  16.2  68.0 31.5 20.9 I6.4  .  •• ••  10.4 '13.1 10.2 10.6  OD  •  .  13.6 13.5  97 Appendix '.. IV.  Continued. Lodgepole pine 2  Ht. N HC  Moisture content measurements  Repl,  OD G  19 12 G  19 12 G  19 12 G  19 12 G  19 12  1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2  62.5 46.7 20.0 20.3 13.8  MT  OD  MT  OD  OD  OD  32.4 44.7 29.5 34.1 26.0 29 2 24.2 111.8. 36.7 91.3 35.5 29.5 37.7 27.4 31.8 25.3 16.1 19.7 15.8 19.6 15.4 20.1 15.4 20.4 16.O 16.5 20.2 16.2 :i9.6 15.7 13.6 10.6 14.0 11.5 13.5 10.8 10.8 13.8 ll.l 13.8 10.9 13.7 10.7 13.5 10.5. 79.6 33.6 42.2 30.5 30.9 24.6 27.7 21.5 80.8 30.8 33.3 25.5 32.8 24.8 20.1 15.6 20.4 15.8 19.2 15.0 20.3 15.7 20.4 16.0 20.2 16.0 20.6 16.4 12.8 10.0 13.5 11.2 13.2 10.5 13.9 10.8 14.0 10.7 13.8 11.4 14.0 11.0 114.3 32.4 35.1 24.6 32.0 23.6 28.9 22.8 97.7 30.8 31.6 24.1 29.3 23.4 20.1 16.5 20.6 16.5 20.3 15.9 20.0 16.0 20.1 16.6 21.1 17.0 20.7 I 6 . 4 13.2 11.6 13.5 10.7 13.1 10.2 13.3 10.2 13.4 11.8 13.6 10.8 13.3 10.3 64.6 32.1 36.1 26.0 28.1 22.4 28.4 22.7 67.8 31.8 • ••• • • • • 29.5 23.0 30.3 23.7 20.6 16.6 21.2 17.3 20.8 I6.4 19.8 15.6 20.6 16.2 20.6 15.8 20.5 16.2 13.7 10.6 13.5 10.4 13.3 10.3 13.8 11.7 13.9 10.8 13.9 10.5 13.5 11.1 125.4.39.5 35.4 24.5 97.4 33.4 29.4 22.4 20.3 16.2 20.1 16.0 20.5 16.3 20.5 16.2 13.4 11.8 13.5 10.4 13.3 11.7 13.2 10.3  (Continue next page)  98 Aouen&ix  IV. Continued. Lodgepole  Ht. N MC  M o i s t u r e content measurements  Repl. OB  G  1 2  19 12 G 19 12  1 2 1 2 1 2 1 2 1 2  G  1 2 1 2 1  1  19  12  19  12 G 19 12  1 2 1 2 1 2 1  2 1 2 1 2  (Continue next  MT  40.6 27.8 45.9 28.1 21.5 17.1  OD  MT  OD  36.7  26.7  35.2 33.4 21.2 20.0  16.9 15.5  24.4  28.5  21.5  15.4 15.1  20.3 15.8  40.3 27.5 21.2 16.8  OD 26.4  24.7  20.5 15.8 13.9 11.0 13.6 10.9  20.4 15.7 13.7 10.9 13.4 10.8  35-4 25.9 45.8 27.9  32.6 31.3 20.0 20.2  13.2 10.5 13.7 10.7  13.5 10.5 13.6 10.3  13.6  31.4 23.3  28.2 21.3 35.2 25.7 21.2 16.6  27.4 20.9  20.6 16.1 20.4 15.7  48.3 32.7 21.3 16.8 21.4 16.7 14.1 10.7 10.7  13.7  25.O 24.5 21.0 I6.5 20.9 I6.5 13.9 10.5  32.4  24.0  34.7 32.9  13.7 10.4 30.8 22.0 30.1 22.1 21.4 16.6 20.4 16.0 14.1 10.6 13.9 10.7  page)  20.7  13.8  13.6 10.8 13.2 10.5 • •••  22.5  16.0 10.5 IO.4  13.9 G  pine 3  • • »• • •• • • ••• • •• •  21.8 ••• •  • •• •  • •• •  • •• •  •*• •  ••• •  • *••  ••• •  13.7  10.4  • • • • • •  20.0 15.4 13.2 10.1  • •• •  •• • • • # • • •  13.7 10.4 13.5 10.3 • •• •  10.4  21.2 16.7  32.1 24.1 20.3 15.5 20.4 15.6  29.3  • »• •  r  #•• ••• ••• •• • • * -* •••  • • • • • •  • • • • • •  • • • • • •  » • • * • •  • ••• • •• • • •• •  • ••• ••• • ••• •  •  • •mm  •  «  *  • ••• • •• •  m • m m m • • •  T  34 2 23  OD  104.0 136.6 21.0 20.3 13.7 13.7 102.4 134.6 20.3 20.1 13.7 13.7  35.8 39.2 17.0 16.2 11.6 11.7 34.5 37.3 15.7 15.6 10.9 11.2 29.1 39.3 16.5 16.2 11.0 11.3 40.2 34.5 15.7 16.0  72.4 120.1 20.8 20.5 13.7 13.9 136.4 96.8 20.5 20.7 13.8 l l . l 13.9 10.9 110.1 35.0 "52.8 30.8 20.3 15.9 21.1 16.2 13.5 11.1 13.3 10.7  99 Appendix  IV.. Continued". Lodgepole  Ht. N MC  (2)  G  19 12 G  19 12 G  19 12 4  G  19 12 G  19 12  Moisture content measurements  Repl.  OD 1 2 1 2 1 2 1 2 1 2 1 2  pine 4  MT 36.3 27.1  65-5 20.4 20.7 13.6 13.2  37.2 17.4 17.7 11.2  10.9 30.4 24.5 32.7 25.3 20.1 20.8 13.0 13.5  16.6  16.9  10.6 10.8  OD  MT 33.1 25.3 66.4 36.1 19.7  20.3  12.9 12.9  17.0 17.8 10.9 10.8  23.8 28.0 24.5 29.8 19.5 16.2 19.1 20.1 16.5 19.6 12.7 10.4 12.6 13.1 10.6 12.9 28.1 22.8 2.7.9 29.6 23.2 20.3 16.8 19. 19.6 15.7 13.6 10.7 12.  29.3 31.3  1 2 1 2 1 2  29.4 31.7 20.6 20.3 13.6 13.4  24.3  1 2 1 2 1 2  29.0  24.3 23.0 17.0  13.6 13.8  11.1 11.2  13.3 12.9  10.5  1 2 1 2 1 2  31.7 31.2 20.6 20.3 13.8 13.1  25.5  31.1  24.9  19.9  16.1  ll'.l  10.7  28.6 20.8  23.4  17.3 16.6 11.0 10.8  20.9 16.9  (Continue next page)  26.1 17.7 16.5 11.1 10.8  OD 31.2 28.1 19.3 19.3 12.7 12.6  12.9  10.3  29.3 23.2 27.6 22.7 20.4 16.5 19.6 15.9  10.7  MT OD 24.5 27 23.0 16.6 16.4 10.8 10.2 22.9 23.2 VJ.9  16.0 10.3 10.4 21.8  23.1  OD 114.7 119.0 20.9 20.5 13.9 13.5 119.7 133.6 20.9 20.5 13.9 13.6 111.5 141.5 :.20.5 20.4 13.7 13.5 133.7 112.8 20.9 19.6 13.9 13.8 130.7 150.2 20.8 20.5 14.0 13.7  37.4 36.5 16.8 16.7 11.4 11.3 36.2 39.3 16.6 16.3 11.1 11.5 35.1 37.6 16.9 16.3 11.5 11.5 36.6 35.7 16.8 16.1 11.8 11.8 40.0 42.0 17.2 16.6 12.0 12.0  100  Appendix  IV. Continued. Lodgepole  Ht.  N MO  (*)• .  pine compression  wood  Moisture content mea 3 u r e r a e n t s 1  OD ' ?!T "  OD  2  OD  3  f.;T ' • OD  4  5  MT  OD  Compression wood  1  G  19 12  26.5 19.8  27.9 21.8 20.7 I 6 ; i  26.5 20.8 20.1 16.4 20.5 16.1  13.6 10.5  13.3 10.4  14.0 10.9  26.5 19.5 20.5 I5.9 13.9 10.8  28.0 22.4 20.3 16.0  14.5 11.7  Opposite wood  1  G  28.4 22.4  26.8 20.5  »•••  ••••  70.3 29.9  19 12  20.5 16.2  19-9 15.5 13.5 11.2  • •••  ••••  • •••  ••• •  14.5 11.7 13.6 10.9  13.9 11.3  101 Appendix  IV. Continued.  Ht. N MC  White snruce Moisture content  Rcol. OD  G  1  19  1  12 G  19  12  2 2 1  2 1  2 1  2 1  2  G  1  19  1  2 2 1  2 G  1  19  1  12  1  G  1  19  1  12  2  2 2 2 2 1  2  (Continue next  MT  OD  KT  OD  27.3 28.7 20.0 20.7 13.8 13.9 33.2 23.5 32.7 34.7 24.3 30.9 32.2 23.0 32.5 22.9 20.7 14-9 20.6 14.5 20.6 20.5 14.7 20.7 14.4 20.5 13.8 10.1 13.8 10.0 13.7 14.0 10.2 13.8 9.9 13.7 32.8 23.7 31.8 23.5 31.0 34.0 23.9 34.1 24.O 32.4 20.0 14.9 20.4 14.7 20.2 21.0 15.5 21.1 15.2 21.1 14.1 10.3 13.9 10.0 13.8 14.0 10.1 13.9 10.0 13.8 29.5 21.4 30.2 22.4 30.3 32.7 22.7 33.2 23.8 32.3 21.5 15.5 21.1 15.O 20.8 21.0 15.1 21.5 15.3 21.0 14.1 10.3 13.9 10.1 13.8 14.2 10.4 13.8 10.0 13.7 30.2 21.4 30.8 21.5 29.2 21.5 30.9 22.3 20.7 14.8 20.4 14.7 20.9 15.1 20.7 14.7 14.0 10.3 13.8 10.1 28.9 28.0 21.0 21.2 14.0  20.6 19.8 15.3 15.9 10.0 14.0 10.0  14.0 10.1  page)  28.2 28.6 20.4 20.6 13.8 13.8  19.8 20.3 14.8 15.1 9.8 9.8  13.3 10.0  MT  measurements OD.  19.6 26.8 19 20.0 28.0 19 14.6 20.8 14 14.9 20.6 15 9.7 14.3 9 9.8 13.8 9 22.8 37.7 24 21.8 14.5 .5 14.5 9.9 10.0 22.6 23.4 14.6 15.4 10.0 10.0 22.3 23.0 15.0 15.2 10.0 10.0  OD  2 7 9 0 9 8  94.2 73.5 20.6 20.3 13.7 14.0  2  103.7 57.5 20.6 20.7 13.6 .13.8 57.0 73.1 20.3 21.2 13.9 13.9 35-5 83.9 20.5 21.0 13.8 13.7  32.5 30.2 15.5 15.2 10.7 10.9 31.9  28.4 15.2 15.1 10.8 10.7 27.9 29.2 15.3 15.7 10.7 10.9 25.O 32.4  15.6  16.0 10.9 10.9 67.6 28.3 91.4 32.8 20.7 15.6 20.8 15.8 14.1 11.2 13.8 11.1  102 Appendix  IV. Continued. Douglas-fir  •Ht. K MC  (0  1  19  1  12  1  1? 12 G 19 12 C-  19 12 G  19 12  2  27.8 32.1 20.9 21.3 13.4 13.6  1 2 1 2 1 2  29.9 28.2 21.1 21.6 13.6 13.4  1 2  29-7 31.4 20.5 20.4 13.5 13.5  2 2  1 2 1 2  1 2 1 2  1 2  1 2 1 2  1 2  content  measurements  _>  OD  G  G  Moisture  Repl.  29.3 29.6 20.7 20.6 14.0 13.6  MT  21.0 24.0  17.1 17.0 11.4 11.5 21.8 20.3  16.4  17.0 11.5 11.4  21.4 23.0  16.5  16.0 11.3 11.0 21.0 20.7 16.6 16.3 11.3 10.9  29.9 21.6 30.1 22.5 20.0 20.6 13.4 13.6  (Continue nezt page)  15.9 16.0 10.9 11.1  OD  MT  26.4 19-5 3 0 . 8 23.1  20.7 20.4 13.2 13.0  16.9  16.5  11.5 10.9  30.2 21.8 30.0 21..7 2 0 . 9 16.6 20.5 15.8 13.1 10.9 13.2 11.0 23.0 2 0 . 5 30.7 21.9 20.0 15.5 20.3 16.3 13.2 1 1 . 1 13.2 10.7 30.7 22.2 27.1 19.8 20.4 1 6 . 4 20.3 15.8 13.7 11.1 13.5 10.6 29.8 21.7 29.0 21.5 20.1 15.6 19.7 15.5 13.3 10.7 13.1 10.5  OD  27.5 29.8 20.2 20.3 13.1 13.1 29.0 29.4 20.7 20.1 13.2 13.0  MT  OD  MT  19.9  26.6 19.7  OD  j  61.4  • • • •• •• • • • • •• • • • « • • • • • • • 20.3 I.5.9 • • • • • • • • • * • •• • • • # • • • • • • • 13.7 10.6 • 0 • • • • • * ... •- • • • • • • • * • • • *  38.0 21.6 21.2 13.8 13.9 64.I 60.0 21.3 20.7 13.5 13.4 42.5 64.8 20.4 20.6 13.5 13.7 71.4 58.4 20.8 19.9 14.0 13.8  •••• • * • •• • • • •• • ••• • • • * • •• • • • • • • •• • • • • • • •• • • •  80.5 81.8 20.4 21.0 13.7 13.4  •• •• •• •• •• ••  22.4 I6.5 16.1  11.1 10.8  20.9 20e 5  16.2 15.2 10.6 10.8  * •• • • ••• • •• • • •• • • •• • • •• •  •* •• •• •• •• ••  •• • ••• *•  19.9 15.9 • • • •• • • •  13.0 10.9  • • • •• • • • •• •• •» •* •• ••  • •• * • • •••*•• • •• • • • * •••• • ••*••• • •• • * •  • • • * «.» • • • » • •• • • • • • * •• • • • • • • •• • * • • • • •• * • • ••• • • • • •  30.5 21.4  .... .... .... .... .... ....  •• • • •••* •• • • •* • • •• *• ••••  MT  33.5 28.6 17.1 17.0 11.8 11.5 36.8  32.8 17.5 16.6 11.4 11.3  31.7 34.2 16.6 17.1 11.0 11.2 37.5 34.0 16.7  15.7 11.4 11.1 39.8 40.5 16.0 16.6 11.2 11.1  103 Appendix  IV. Continued. Subalpine f i r  Ht. N.MC  Re_l. OD  G 19 12 G  19  G 19 12 G 19 12 G 19 12 (End)  1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2  1  45.3 55-9 20.7 20.8 13.4 12.8 38.2 35.3 20.5 20.3 13.2 13.0  MT  OD  27.5 29.6 16.1 16.8 10.8 10.8 25.8 23.6 15.9 15.8 10.2 9.9  2  Moisture  3  WT  OD  28.1 29.4 20.0 20.2 13.0 13.3  21.3 20.9 15.3 15.3 10.2 10.2  37.5 34.4 20.2 20.3 13.2 13.3  26.4 24.3 15.3 15.3  23.1 29.5 20.0 20.2 13.1 13.4 29.7  content measurements 4 5 MT OD MT OD MT  20 21 15 15 10 10 21  34.3 24.5  65.4 30.8 20.5 15.7 20.3 15.7 13.4 10.6 13.6 10.6  60.4 29.6 48.7 29.1 20.4 20.2 13.6 13.5 40.1 43.8 19.8 19.6 13.3 13.1  16.2 16.1 10.4 10.5 26.4 27.1 15.5 14.8 10.7 10.5  13.5 10.3  30.6 34.6 19-4 20.0 13.3 13.4  35.7 37.1 20.5 20.6 13.4 13.5  65.8 49.8 20.4 20.6 13.3 13.4  21.5 23.3 15.1 15.3 10.3 10.4 30.8 30.5 16.2 I6.5 10.6 10.9  48.2 28.3 48.3 27.8 19.9 16.0 20.0 16.2 13.3 10.9 13.1 10.7 36.2 26.1 39.2 23.5 20.0 16.2 20.4 16.5 13.7 10.6 28.4 29.1 I6.4 I6.5 11.0 11.0  10.1 10.2 27.4 20.2 35.1- 24.7 19.6 15.3 19.5 15.4 13.2 10.2 13.0 10.2  36.4 28.0 19.6 15.6 13.4 10.5  Appendix V. Power-loss moisture meter (Moisture R e g i s t e r , Model L) measurements (MT-rad1a1, MTt a n g e n t i a l ) on wood samples from t r e e s o f the study compared t o oven-dry (OD) c a l c u l a t i o n s ; I n c l u d i n g nominal moisture l e v e l s (N MC) a t stem heights (Ht.) and f o r two r a d i a l r e p l i c a t i o n s (1-4 heartwood, 5 sapwood). Observations are 2 f o r each reading. Ht. 1  .,- „ , N MC Repl. {%)  19 12 6  1 2 1 2 1 2  ' OD -20.7 21.1 13.6 13.8 7.7 7.8  1  G  2  2  19  1 2  12  6  1 2  1 2  20.5 20.6 13.5 13,5 7.6 7.7  1  G  2.  3  19  1 2  12  1  2  6  1  2  21.4 21.2 13.9 13.5 7.9 7.8  1  G  2  4  19  1 2  12  1 2  6  1 2  G  20.9  20.8 13.6 13.2 7.9 7.7  1 2  (Continue next page)  , MT-R MT-T 33.2 34.2 33.8 34.9 21.9 22.2 21.5 22.5 17.8 18.0 17.6 18.2 0.377 0.371 32.0 32.8 32.4 33.1 21.6 21.8 21.3 21.4 17.6 17.8 18.0 18.3 0.380 0.375 34.4 3 6 . 0 33.6 3 4 . 0 22.3 22.5 21.5 22.1 17.6 17.8 17.9 18.1 0.368 0.372 32.0 32.6 33.4 34.5 20.5 20.8 21.3 21.9 17.3 17.5 17.9 1 8 . 0 0.354 :  1  0.387  Lodgepole pine 1 Moisture content measurements 5 , OD ' MT-R MT-T OD MT-R MT-T OD MT-R MT-T 20.5 30.9 31.5 20.2 30.2 31.2 19.6 29.9 29.6 20.8 31.4 31.9 20.3 30.8 31.6 19.9 30.0 31.0 13.5 20.8 21.3 13.3 20.9 21.2 13.2 20.5 21.0 13.6 21.3 21.5 13.4 20.9 21.2 13.3 20.6 21.7 7.6 17.4 17.5 7.6 17.5 17.9 7.9 17.5 17.8 7.8 17.7 18.1 7.7 17.9 18.4 8.0 17.5 17.9 0.382 0.396 0.378 0.380 0.388 0.386 19.8 29.7 30.6 20.4 31.8 32.9 20.4 30.5 31.6 19.7 31.2 31.9 13.3 20.9 21.0 13.6 22.4 22.7 13.0 21.7 22.1 13.5 21.1 21.1 7.8 17.8 18.0 7.8 18.0 18.5 8.0 18.3 18.5 7.6 17.7 18.2 0.397 .... 0.373 0.423 0.403 20.6 30.6 31.3 20.7 32.4 33.8 19.8 31.5 32.6 20.3 32.0 33.3 13.2 20.9 21.4 13.2 21 .1 22.5 .... 13.1 21.1 22.5 13.5 21.5 22.1 7.7 18.3 18.6 7.6 17.7 18.2 7.7 18.2 18.5 7.5 17.8 18.4 0.397 .... 0.375 0.404 .... 0.412 20.7 30.3 30.7 20.1 30.9 32.1 20.5 30.5 31.4 13.2 20.9 21.9 13.1 21 .0 22.2 13.6 22.1 22,6 7.5 18.1 18.8 "7,7 18,1 18,5 7.6 18.1 1 8 . 1 0.387 0.390 .... • A  0.395  J  :  OD 20.7 20.5 13.7 13.7 7.8 7.6  20.9 20.7 13.8 13.6 7.8 7.7  21.2 20.8 13.8 13.7 7.8 7.9  20.9 20.9 13.6 13.5 7.9 7.9  MT-R MT-T 33.5 34.0 33.2 33.8 22.4 22.6 22.6 23.0 18.4 18.5 18.2 18.5 0.363 0.369 34.2 34.7 33.8 34.3 23.0 22.8 22.0 22.5 17.8 18.3 18.2 18.5 0.370 0.373 33.6 33.6 33:4 33.6 21.9 22.2 21.7 22.0 18.6 18.5 18.1 18.6 0.377 0.374 32.9 33.9 33.9 35.5 21.3 22.0 21.9 22.0 17.7 18.1 18.3 18.5 0.358 0.367  Appendix  Ht.  V. Continued".  NMCRepl. W 1 19 2 1 12 2 1 2 1 2 19 1 2 12 1 2 6 1 2 1 2 19 1 2 12 1 2 6 1 2 1 2 19 1 2 12 1 2 6 1 2 1 2 19 1 2 12 1 2 1 2 1 2  j MT-R MT-T 33.6 34.2 33.4 34.9 22:5 23.1 22.5 22.9 18.118.3 17.6 17.9 0.396 0.376 20.4 32.3 32.4 20.6 32.0 33,1 13.2 21.4 22.0 14.0 21.8 22.2 7.6 17.8 18.1 7.7 18.1 18.2 0.366 0.369 20.6 31.6 33.2 21.1 32.0 33.2 13.5 22.0 22.8 13.6 22.3 23.5 7.8 18.5 18.5 7.8 18.4 19.0 0.384 0.386 21.2 36.5 37.0 20.6 33.8 33.8 13.7 23.1 23.5 19.9 23.8 23.8 7.9 19.3 19.6 8.0 18.9 18.9 0.418 0.407 20.1 33.5 34.9 20.5 32.7 32.6 13.5 '3.4 22.9 13.'2 23^0 2 3 J 7.8 18.4 18.7 7.9 19.019.2 0.386 0.405 .  OD 20.0 20.4 13.8 13.8 7.8 7.7  (Continue next page)  Lodgepole pine""? Moisture content measurements 2 • " 3 • 4 OD MT-R MT-T OD MT-R MT-T OD MT-R MT-T 19.7 31.6 32.4 19.8 30.2 32.2 19.4 29.6 30.1 20.2 32.5 34.0 19.6 30.7 31.7 13.5 21.8 22.6 13.6 21.9 22.3 13.4 21.9 21,7 13.7 22.2 22.7 13.5 22.1 22.3 7.5 18.3 18.6 7.5 17.7 18.3 7.7 18.0 18.5 7.6 18.4 18.5 7.6 18.0 18.5 0.395 0.384 0.413 0.389 0.403 .... 19.2 29.9 31.0 20.3 29.3 30.1 20.4 31.2 31.4 12.8 21.5 22.1 14.0 21.121.6 13.9 21.9 21.9 7.7 17.8 18.2 7.7 17.5 17.9 7.6 18.1 18.3 0.404 0.376 .... 0.368 .... ..... 20.3 30.2 31.1 20.0 30.7 32.2 20.7 31.8 33.0 13.121.4 22.0 13.3 21.8 22.2 13.3 21.8 22.5 7.7 18.1 18.6 7.8 18.2 18.5 7.8 18.4 19.0 0.369 0.418 .... 0.396 •••• 20.8 31.5 32.7 19.8 30.3 31.4 ,. 20.6 30.7 32.2 13.5 21 .8 21.5 13.3 21.9 22.9 .• 13.9 22.2 23.0 7.7 18.0 18.1 7.8 18.1 18.2 8.018.2.8.5 0.371 0.381 -0.371 .... ..'. ....  •••• ••••  •-• ••••  OD HT-R MT-T " 20.131.6 32.8 20.4 33.7 34.1 14.0 22.3 22.3 13.8 23.4 23.6 7.7 17.5 17.6 7.8 18.4 18.7 0.353 0.365 20.131.9 33.2 20.2 32.7 34.2 13.5 22.7 23.2 13.8 22.7 23.2 7.5 18.0 18.5 7.6 18.5 18.8 0.363 0,372 20.132.7 33.8 20.1 33.7 34.2 13.2 22.7 22.3 13.4 23.5 23.5 7.3 18.2 18.2 7.7 18.5 18.9 0.360 °20.6 32.2 32.4 20.5 31.8 32.3 13.8 22.4 22.7 13.5 23.0 23.0 7.8 18.0 17.8 8,018.418.4 0.358 0.367 20.3 32.5 33.0 20-5 33.2 33.5 13.4 23.0 23.1 13.3 22.8 23.1 7.9 18.5 18.7 8.0 18.4 18.9 3 7 5  ^364 °  Appendix  V. Continued. Lodgepole pine 3  Ht. 1  N MC Repl. W 19 12 6  G 2  19 12 6  G 3'  19 12 6  G 4  19 12 6  G 5  19 12 6  G  1 2 1 2 1 2 1 2  OD  y. MT-R MT-T  21.5 35.8 36.9 20.5 34.9 35.5 13.9 25.1 25.5 "13.6 25.125.0 7.9 20.120.4 7.6 20.0 20.3 0.441 0.438  1 2 1 2 1 2  ,°0.6 20.4 13.2 13.7 7.9 7.7  32.2 33.8 32.5 34.2 24.7 25.6 25.2 25.6 18.7 19.2 19.6 20.0  Moisture content measurements  ?  OD  21.2 20.4 13.7 13.4 7.7 7.5  MT-R MT-T  34.8 36.4 34.4 35.0 25.5 25.3 24.7 25.1 21.0 20.9 20.0 20.2 0.454 0.434  20,0 30.4 31.8 20.2 30.5 32.7 13.5 24.4 24.9 13.6 25.0 25.1 7.5 19.8 19.9 7.7 20.3 20.3  OD  MT-R MT-T  21.2 34,9 35.2 20.0 32.8 34.0 13.6 25.8 26.1 13.2 24.8 25.1 7.6 21.4 21.2 7.4 20.3 20.5 0.469 0.442  MT-R MT-T  20.7 33.6 33.7  13.4 25.8 26.2 7.6 21.4 21.7 0.479 ....  20.3 32.5 33.6  7.6 20.5 20.8  0.426 0.399  0.430 0.425  0.451 ....  2 1 2 1 2  1  21.3 34.8 36.4 21.4 36.3 38.4 13.9 24.2 24.7 14.1 25.4 25.3 7.9 19.2 19.5 8.0 20.4 20.6  21.2 32.9 34.1 20.7 32.9 33.8 13.8 24.4 24.6 13.7 25.4 25.9 7.9 19.6 19.9 7.8 20.7 20.7  21.2 32.3 32.5  1 2  0.404 0.417  0.407 0.430  1 2 1 2 1 2 1 2  21 .0 34.1 35.0 20.9 33.5 34.6 13.9 24.7 25.4 13.7 24.0 23.8 7.9 19.6 19.7 7.7 19.7 19.6 0.397 0.402  20.3 32.3 33.3 20.4 31.9 33.3 13.7 25.3 25.7 13.5 23 7 24.8 7.8 20.4 20.4 7.7 20.0 20.2 0.428 0.417  1 2 1 2 1 2  21.4 36.5 37.2 20.4 32.3 33.1 14.125.6 25.8 13.9 25.0 25.1 8.1 21.1 20.8 8.0 20.4 20.5  20.0 32.134.6  1 2  0.426 0.412  .... ....  13.7 26.3 26.2  .... ....  20.8 33.7 34.2 20.5 33.2 33.6 13,7 25.0 25.4 13.9 24.7 24.8 7.7 20.7 20.6 7.9 19.119.2  .... ....  0.412 0.395  .... ....  20.5 35.0 36.0 20.7 33.7 34.1 13.8 25.0 24.9 13.9 24.2 24.3 7.8 19.6 19.6 8.0 20.2 20.3 0.412 0.384 20.3 34.4 35.3 21.1 36.1 36.4 13.5 25.4 25.8 13.3 24.5 24.2 7.8 20.4 20.8 7.8 20.0 20.0  13.2 24.5 24.6 7.6 20.8 21.0  0.450  MT-R MT-T  21.0 38.0 38.9 20.3 37.5 38.2 13.7 26.9 27.2 13.7 25.9 26.0 7.8 21.4 21.3 7.8 20.0 20.3 0.447 0.411  0.436 0.402  •  7.2 20.6 20.7 0.429 .... .  OD  20.3 34.0 34.7 . 20.133.5 32.8 13.7 25.7 26.0 13.7 25.0 25.3 7.7 20.5 20.2 7.7 19.119.2  13.6 25.4 26.2  1 2  (Continue next page)  OD  ....  ....  0.426 0.422  Appendix  Ht. 1  V. Continued.  N MC  Repl. •  (30  19 12 6  19 12 6  19 12 6  19 12 6  19 12 6  OD 1 2 1 2 1 2 1 2  20.4 20.7 13.6 13.2 7.7 7.5  1 MT-R MT-T 38.3 38.5 38.7 39.1 25.1 25.6 24.6 24.8 19.7 20.3 20.3 20.4 0.432 0.428  OD  Lodgepole pine 4 Moisture content measurements 3 4 2 OD MT-R MT-T 00 MT-R MT-T MT-R MT-T  19.7 20.3 12.9 12.9 7.4 7.2  34.4 35.7 37.1 38.7 24.4 24.5 23.6 23.8 19.7 20.2 20.2 20.3  19.3 19.3 12.7 12.6 7.3 7.1  33.0 33.6 24.3 22.9 20.0 19.9  0.428 0.431  0.435 0.432  34.0 34.0 24.2 23.5 20.0 20.0  13.0 24.4 24.7 7.6.20.6 20.6 0.453 ....  1 . 2 1 2 1 2 1 2, 1 2 1 2 1 2  20.133.6 35.0 20.8 35.3 36.8 13.0 22.0 22.7 13.5 23.1 23.4 7.5 18.7 19.3 7.7 18.7 19.0 0.401 0.397 20.6 36.7 37.2 20.3 34.0 36.4 13.6 23.5 24.3 13.4 22.6 23.5 7.8 19.5 19.9 7.7 18.4 18.8  19.5 32.9 34.0 20.1 33.7 34.6 12.7 22.8 23.3 13.1 23.0 23.4 7.3 19.5 19.7 7.5 19.0 19.3 0.425 0.419 20.3 34.2 35.3 19.6 31.9 33.2 13.6 23.6 24,3 12.9 22.8 23.2 8.0 20.5 20.7 7.5 18.9 19.2  19.132.5 33.5 19.6 32.7 33.6 12.6 23.1 23.9 12.9 22.6 22.7 7.2 19.9 20.6 7.5 18.4 18.7 0.443 0.416 19.4 32.8 33.2  1 2 1 2 1 2 1 2  0.426 0.396 20.8 33.5 34.4 20.9 34.0 35.3 13.6 24.0 24.4 13.8 23.5 23.4 8.0 19.4 19.5 7.8 18.0 18.2  0.444 0.415 20.4 33.9 34.4 19.6 31.5 32.6 13.3 24.0 24.3 12.9 22.9 23.5 7.4 19.2 19.3 7.4 17.9 18.3  0.444 ....  1 2 1 2 1 2 1 2  0.420 0.396 20.6 35.8 36.5 20.3 38.0 39.6 13.8 24.2 24.6 13.1 24.6 25.0 7.8 19.2 19.2 7.7 19.9 20.2  0.430 0.410 19.9'34.4 35.6  1 2  0.421 0.457  .(Continue next page)  19.4 33.6 34.0  12.9 24.3 23.7 . 7.4 20.3 20.5  .... ....  .j. .... .... ............  \  ....  .... '  13.3 24.2 23.9 7.5 19.1 19.0 0.422  ....  ....  OD 20.9 20.5 13.9 13.5 7.8 7.7  5 MT-R 36.5 36.0 25.2 23.8 20.8 20.2  MT-T 37.0 36.5 25.9 24.0 21.2 20.3  0.405 0.378 20 9 36 0 37 1 20.5 35.3 36.2 13.9 24.4 24.5 13.6 24.0 24.0 8.0 20.2 20.3 7.8 19.0 19.0 0.392 0.381 20.5 35.1 36.2 2C.4 35.0 36.1 13.724.7 24.6 13.5 23.8 24.1 7.8 19.7 19.5 7.7 18.8 18.9 0.399 0.371 20.934.634.9 19.6 32.133.0 13.9 25.124.9 13.8 24.4 24.4 7.8 19.2 19.2 7.5 18.7 18.7 0.390 0-385 20.8 38.8 39.5 ?0.5 38.0 37.5 H.O 25.9 25.8 13-7 25.1 25.1 7.9 9.8 9.3 7.8 19.3 19.3 0-398 0.386  Appendix  Y. Continued.  Compress Ionvwood  20.5 36.7 37.6  20.5 36.6 36.9  21. 4 39.3 39.6  13.3 25.5 25.9  14.0 29.1 29.1  13.9 29.0 29.7  14, 5 29.8 29.7  8.0 22.6 23.2  7.9 25.1 25.0  8.2 24.0 24.0  8.2 24.3 24.3  5 25.1 24.8  0.508  0.584  0.540  0.541  19  1  20.7 38.6 38.0  20.1 38.0 39.3  12  1  13.9 27.8 29.3  6  1  G Opposite wood 19  1  20.5 35.0 35.6  19.9 32.7 34.0  12  1  13.6 24.8 25.3  13.3 25.5 25.9  6  1  7.7 19.6 19.6  7.6 20.8 21.3  0.444  0.462  G (Contlnuenext page)  0.525 20, 3 33.9 35.0 13, 6 27.5 27.8 ,2 22.5 23.0 0.498  Appendix  Ht.  V. Continued.  N MC {%) 19  Repl. 1 2  12  1 2  6  1 2  6  OD  1 .:. MT-R MT-T  21.0 21.2 14.0 14.0 8.0 8.1  29.2 29.9 29.3 30.2 19.7 20.1 19.7 19.7 16.1 16.3 .16.8 16.9 0.334 0.331  1 2  2  19  1 2  12  1 2  6  1 2  G 3  1 2 1 2  6  1 2  G  20.2 21.0 14.1 14.0 8.0 8.0  1 2  12  1 2  6  1 2  21.5 21.0 14.1 14.2 8.1 8.1  2 1 2  12  1 2  6  1 2 1 2  (Continue next page)  20.6 .20.7 13.8 13.8 8.0 8.1  27.4 29.0 27.5 29.3 20.0 20.8 19.4 20.2 16.4 17.1 16.2 16.7  32.0 31.9 31.2 32.0 20.5 21 .5 21.2 21.5 17.3 17.1 17.0 17.6  20.7 20.9 14.0 14.0 8.1 8.1  29.8 30.5 29.5 30.6 21.8 22.8 20.9 21.4 17.8 18.0 17.4 17.5. 0.347 0.341  content measurements 3 4 MT-R MT-T OD MT-R 20.8 27.3 24.9 26.7 25.7 27.4 20.6 25.4 14.3 "19.8 19.7 20.8 13.8 19.7 19.2 19.5 8.3 16.5 16.0 16.5 7.9 16.3 16.1 16.4  0.302 0.298  0.305 0.301  0.329 0.310  26.5 27.0 18.6 20.1 16.2 16.6  20.5 27.6 29.3 .... • • • . • • 13.6 19.5 19.9 • • • .... • 7.8 16.6 17.0 ....  26.3 26.8 19.2 18.6 15.8 16.0  28.5 27.5 19.6 18.9 16.0 16.4  20.6 20.5 13.7 13.7 7.9 7.9  20.4 21.1 13.9 13.9 7.9 8.0  26.0 26.9 28.9 28.9 19.6 20.3 19.8 20.2 16.3 16.7 16.5 16.8  20.2 21.1 13.9 13.8 8.0 7.8  0.317 0.313 21.1 21.5 13.9 13.8 7.9 7.9  29.2 30.0 30.9 31 .2 20.2 21.3 19.9 20.2 17.0 17.3 17.4 17.7 0.333 0.333  20.4 20.7 13.8 13.8 8.0 8.0  27.8 29.4 28.1 29.9 31.0 21.2 21.0 21.0 17.0 17.3 17.3 17.4 0.332 0.333  27.4 28.3 20.0 21.1 16.7 17.4  0.315 0.320  0.310 0.303  0.356 0.355  1  19  29.8 28.0 19.4 19.6 16.0 16.5  0.325 0.311  1 2  19  28.7 27.3 19.1 19.5 16.0 16.3  0.309 0.302  2  12  4  20.7 20.5 13.8 14.0 8.0 8.0  1  19  OD 20.4 20.6 13.8 13.8 7.8 8.0  White spruce • Moisture 2 MT-R MT-T OD 20.0 25.7 27.7 20.7 26.6 27.9 13.8 19.0 19.6 13.9 18.8 19.6 7.8 16.2 16.2 8.0 15.8 16.0  20.8 21.0 13.8 13.7 8.0 7.9  MT-T 27.3 26.9 20.2 20.2 17.1 16.4  OD 20.6 20.2 13.7 14.0 7.9 8.0  • 5 MT-R 31.3 29.2 21.0 21.6 17.5 17.2  MT-T 33.2 30.5 21.4 22.1 17.7 17.2  0.334 0.325 20.6 •20.7 • 13.6 13.8 7.8 8.0  31.5 30.0 21.6 20.9 17.4 17.1  32.2 31.2 21.2 21.4 17.5 17.1  0.340 0.328  0.327 ....  25.4 27.1 27.3 28.6 20.2 20.7 20.0 20.0 16.8 17.1 16.7 16.8  .. *. .... 20.3 21.2 • • • ••*« • .... .... • • • • 13.9 13.9 •••• 8.0 .... •••• .... 8.0 .... • . . .... •  29.1 31.7 21.2 21.0 17.4 17.4  0.326 0.320  .• * .... •••• .•«. •••• .... • • • •••• • •*•• *••• . . • •••• • — .... —  0.338 0.335  28.8 29.4 20.2 19.6 17.5 16.9  30.0 30.2 20.9 20.4 17.6 17.0  0.;336 0.334  20.5 21.0 13.8 13.7 8.0 8.0  32.0 31.9 22.1 21.4 18.0 18.2  0.355 ....  20.7 . . ..... 20.8 14.1 13.8 «••• ... . • •. 8.2 .... . • •". 8.1 . • • • .•• • • . • . .... • •• •  32.2 31.3 21.2 21.2 18.1 17.7  31.0 32.0 21.6 21.6 17.6 17.6  .... *  id.341  31.0 32.3 22.9 21.8 18.2 18.0  32.4 35.0 23.0 22.3 18.4 18.2  0.364 0.350  Appendix  Ht.  V. Continued.  Douglas-fir Moisture content measurements N' MC Repl. T —1 3 . 4 (*) - p p MT-R Mi-r Ob M.-kMr-T, OD Hl-KHT-T Ob Ml-k MT-T 1 20.9 29.0 29.8 20.7 29.129.3 20.2 29.8 30.8 19.9 29.5 29.8 19 2 21 .3 29.5 30.9 20.4 29.8 30.0 20.3 29.4 29.9 ........ .... 1 13.4 24.0 23.1 13.2 24.4 25.5 13.1 25.7 25.9 13.0 25.6 26.3 12 2 13.6 24.0 24.9 13.a 24.5 25.1 13.1 25.9 26.0 1 7.9 21.9 22.2 7.7 22.3 22.5 7.6 23.6 23.6 .7.6 24.7 24.8 2 8.1 21 .1 21 .8. 7.7 22.0 22.3 7.7 23.1 23.4 1 2 1  1 9  2  1  12  2 1  > 2•  1 2 19  1 2  12 6  1 2 1  2  1 2 19  12  1  2 1 2  6  1  2  1 '2 19  1 2  6  '  1  2  1 2  1  2  1 2 (Continue next page)  0.442 0.434 21 .1 28.1 28.4 21.6 30.1 31.8 13.6 23.4 23.8 13.4 23.1 22.8 8.0 20.9 2 K 2 7 S 20.5 ?n.5 20.8 7.8 20.8  0.447 0.458 20.9 29.4 30.6 20.5 28.5 28.8 13.1 24.3 24.3 13.2 23.0 23.4 7.6 21.6 21 .7 7.8 20.9 21.1 21.1  0.483 0.478 20.7 29.3 30.0 20.1 27.8 28.5 13.2 24.9 25.4 13.0 23.7 24.1 7.5 22.4 22.5 7.7 22.3 22.4  0.414 0.406 20.5 29.4 20.3 20.4 26.4 27.5 13.5 22.8 23.8 13.5 23.1 23.5 7.8 20.3 20.7 7.a 20.0 20.5  0.430 6*425 20.0 26.4 27.4 20.3 28.8 27.9 13.2 24.0 23.1 13.2 24.2 24.2' 7.7 21 .7 21.7 7.7 21 .1 Zl.3  0.456 6.448  0.405 0.403 20.7 27.5 29.3 20.6 26.8 27.6 14.0 23.7 24.5 13.6 23.0 23.4 7.9 20.9 21 .1 7.8 20.6 21.0  0,432 .... 0.434 20.4 27.9 27.9 20.3 26.6 26.8' 20.3 27.2 26.9 13.7 24.2 24.7 13.7 23.7 24.0 13.5 23.6 23.8 7.8 21.5 22.0 7.8 21 .5 21.7 7.7 21.0 21 .5  ....  0.425 0.423 20.0 27.7 28.7 20.6 28.3 29.7 13.4 24.6 24.9 13.6 24.8 25.4 7.8 21.7 22.1 7.9 21.3 22.2  0.429 0.424 20.1 28.6 28.9 19.7 27.5 27.0 13.3 25.2 25.2 13.1 24.7 25.6 7.7 21 .9 22.0 7.8 21.4 21.9  0.430 ....  ' ....  ....  ....  0.442 0.439  0.442 0.437  ,  0.507  5 UU m - R M I - l . 21.6 41.3 43.5 21 .2 35.6 38.3 12.8 29.2 29.2 13.9 28.7 23.9 8.0 25.8 26.0 8.0 24.7 25.7  0.513 0.503 21 .3 35.8 38.4 .... 20.7 36.0 35.8 13.5 27.4 26.8 13.4 25.3 25.8 7.7 24.0 23.5 7.9 23.6 23.8 0.477  ....  0.473 20.4 32.0 33.3 20.6 33.9 34.7 13.5 Z6.2 25.8 13.7 26.7 26.7 7.9 22.9 22.9 7.7 22.6 22.4  :  0.455 °20.8 33.4 24.5 19.9 32.4 33.6 14.0 26.7 26.7 .... 13.8 25.2 25.1 8.0 22.8 23.1 7.9 22.1 22.8 458  .•  0.448 0.432 20.4 33.5 33.5 21.0 33.3 34.1 13.7 25.9 26.4 13.4 25.2 25.7 7.9 22.3 22.3 8.0 21.8 21.8 0.440 0.425  Appendix  Ht.  V. Continued.  N MC Repl; <*> —OD 19  1 2  12  1  2 6  1  2 1 2 19  1  1  2 6  1 2  1 • 2 19  1 2  12  1 2  6  19  1  •I 1 2 1 2  12  1 2  6  I 2  1 2 19  1 2  12  1 2 1 2  1 2 (End)  20.7 39.0 39.5 20.8 35.0 35.5 13.4 24.6 24.8 12.8 22.0 22.7 7.6 19.0 19.2 7.7 18.9 18.9 0.416 0.414  2  12  1 ' MT-RMI-I  Subalpine f i r Moisture content measurements 2~—^ 3 4 OD Ml-kMI-T OD MT-R MT-T OD Hi-R MT-T  QU  20.0 31.8 33.4 20.0 31.2 31.3 30.2 30.6 20.2 27.8 29.7 13.0 24.1 24.4 13.1 24.0 24.1 13.3 23.7 24.2 13.4 23.0 23.6 7.3 19.7 20.4 7.3 19.5 19.8 7.5 19.4 19.8 7.5 19.9 19.8  20.5 20.3 13.4 13.6 7.6 7.7  20.2  0.430 0.413  19.9 34.5 20.0 34.3 13.3 23.5 13.1 22.4 7.7 17.5 7.6 17.1  36.0 .. 19.6 31.4 31.8 34.7 19.5 29.8 30.6 23.8 13.2 23.6 23.7 22.6 13.0 21 .9 22.4 17.7 7.5 18.5 18.5 1/.4 7.4 18.3 17.9  0.385 0.367 20.0 33.8 33.9 20.4 33.2 33.7 13.7 23.7 24.1 13.5 22.8 23.6 7.7 17.2 17.3 7.9 1/.0 17.4 0.379 0.364 20.5 34.5 34.9 20.6 34.2 34.8 13.4 24.0 2 4 . 2 13.5 23.9 24.4  7.7 i7.o i8.i 7;7 16.8 18.0 0.368 0.363  0.385 0.373 19.6 32.0 32.2 13.4 23.5 23.6 7.5 17.1  17.6  0.406 0.406  0.428 0.404  20.5 33.8 34.6 20.2 31.2 31.4 20.1 30.4 30.8 20.3 31 .3 32.4 20.3 30.4 34.6 13.2 31 .8 23.7 13.2 22.4 22.6 13.3 22.9 23.4 13.0 21.7 23.0 13.3 22.2 22.6 7.5 16.6 17.3 7.5 17.8 18.3 V7.5 18.0 18.3 7.3 16.7 17.4 7.7 18.6 18.3 " 0.360 0.388 0.377 0.375 0.380  '..  ....  MT-R MT-I 21.5 32.8 28.9 30.4 23.5 24.2 24.2 24.6 19.8 19.7 19.6 19.9  .  20.4 30.4 30.8 20.2 29.6 30.1 20.2 29.6 13.6 24.1 24.3 " "23.8 24.1 13.5 7.8 19.5 19.4 7.6 18.6 18.4 e  1  0.403 0.403 19.8 19.6 13.3 13.1 7.5 7.5  29.7 30.5 22.9 22.5 17.8 18.5  30.1 29.7 23.2 23.0 18.0 18.6  0.378 0.383 19.4 20.0 13.3 13.4 7.6 7;7  27.8 28.6 28.9 29.3 22.4 22.4 22.0 22.2 17.4 17.0 17.5 17.7 0.368 0.363  0.383 20.4 20.6 13.3 13.4 ~'Z 7.5 7.5 '  30.0 30.4 28.9 29.7 21 .7 22.3 20.9 21.6 16.7 17.4 16.6 17,0 0.353 0.342