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The dissipation factor method of ascertaining the moisture content of newsprint Chu, Gan Dick 1949

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L £ * & 7 THE DISSIPATION FACTOR METHOD OF ASCERTAINING THE MOISTURE CONTENT OF NEWSPRINT Gan Dick: Chu A Thesis Submitted i n P a r t i a l Fulfilment of The Requirements for the Degree of MASTER OF APPLIED SCIENCE In the Department of MECHANICA1 AND EIECTRICA! ENGINEERING Approved: In Charge of Major Work . fie&d dt Department. THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1949 THE DISSIPATION FACTOR METHOD OF ASCERTAINING THE MOISTURE CONTENT OF NEWSPRINT by Gan Dick Chu Ever since newsprint was made on a mass production basis, there has been a real need for a simple and instantaneous measurement of the moisture content of the moving sheet. A knowledge of the moisture content i s important both economi-cally and technically to the m i l l operator. As newsprint i s sold by weight, the moisture content of the paper must be maintained within a narrow specified range. The m i l l , natur-a l l y , strives to produce paper with as high a percentage of moisture as permissible. Without any sc i e n t i f i c means to guide them, however, the machine operators tend to overdry the paper because an overdried sheet is not nearly so noticeable as one that i s too moist. This means that less paper i s being made than i s practically possible for each cord of wood pro-cessed. In addition, the overdried paper i s of inferior quality to that containing the proper amount of moisture. At present, the only reliable method of measuring moisture con-tent i n Canadian mills i s the laborious oven method which, though undoubtedly very accurate, has the great disadvantage of time lag. The recent development of the Q-meter offers a method f o r the rapid measurement of the moisture content of the moving sheet by the d i s s i p a t i o n factor method which has the advantage that no contact with the paper i s required, The f a c t that the d i e l e c t r i c constant of water i s very high compared to that of c e l l u l o s e suggests that the d i e l e c t r i c losses i n moist paper could be used to measure i t s moisture content* Tests were therefore conducted i n the lab-oratory with a Boonton Q-Meter, type 160-A, to determine the d i s s i p a t i o n f actor of newsprint samples of various moisture contents. A p a i r of plates with the sample of newsprint be-tween them, but not touching, constitutes the test condenser. The d i s s i p a t i o n factor of t h i s condenser depends l a r g e l y upon the amount of moisture contained i n the newsprint. To mea-sure the d i s s i p a t i o n f a c t o r , the test condenser i s tuned to resonance with a high-Q inductor. The amplitude of resonance depends on i t s <£ value which i n turn i s l a r g e l y a function of the condenser losses. Henoe the d i s s i p a t i o n factor may be calibrated against the percentage moisture content. Results of laboratory tests at d i f f e r e n t humidities and various frequencies showed that the percentage moisture content can be measured with adequate accuracy. The speed test s showed that the speed of the paper up to a v e l o c i t y of 1800 feet per minute between the condenser plates has no e f f e c t on the readings. A l l these preliminary tests i n the laboratory indicate that i t i s feasible to apply the Q-meter for measuring the moisture content of the moving sheet by -fflie d i s s i p a t i o n factor method. Exhaustive f i e l d tests under actu a l m i l l production conditions should be made over a period of time to compile s u f f i c i e n t data f o r a f a i r appraisal of the p r a c t i c a l value of t h i s method. . £ TABLE OP CONTENTS PAGE I Introduction 4 I I Review of l i tera ture 6 I I I Survey of Exis t ing Methods of Measurements . . . . . 10 17 Investigation •• 15 A. Theory of measurement • • • • 15 1. Composition and d ie lec t r ic constant of paper 15 £• Ideal condenser c i r c u i t . . . . 16 3. Ideal resistor c i r cu i t 17 4. Imperfect condenser c i r cu i t 17 5. Equivalent c i r cu i t for imperfect condenser • • • • • 18 B. Description of test c i r cu i t and apparatus . . SO 1. Test c i r cu i t and analysis • £0 £. Q-meter theory • • £6 3. Test condenser assembly and humidity chamber £9 4. Test assembly for effect of speed of paper 31 C. Experimental results 34 1. Procedure • 34 (a) Stationary tests 34 (b) Speed tests • 35 £. Observations ' 36 (a) Data, of stationary tests 36 (b) Data of speed tests 36 3 7 Discussion and Prospectus 4S 71 Literature c i t e d 45 711 Acknowledgment... 48 T i l l l i s t of Symbols 49 IX Graphs • 51 X Appendix • 5 7 4 THE DISSIPATION FACTOR METHOD OF ASCERTAINING THE MOISTURE CONTENT OF NEWSPRINT I INTRODUCTION From the economic point of view, i t i s desirable i n 'a. paper m i l l to be able to measure the amount of moisture i n the sheet of newsprint while i t i s moving through the paper machine. Because newsprint i s sold by weight and t h i s weight depends la r g e l y upon the water contained i n the paper, the purchaser s p e c i f i e s that the water content s h a l l be kept below & certain maximum. On the other hand, the paper m i l l s t r i v e s to produce paper with as high a moisture content as permissible because the higher the moisture content, the le s s i s the amount of cellulose bulk per ton. Hence a m i l l must maintain the percentage moisture content of i t s newsprint with i n a narrow range. A t y p i c a l working range i s from 7 to 1 0 per cent. The advantage of measuring the moisture content i n the moving newsprint before i t i s wound up i s that there i s s t i l l time f o r making adjustments to the dryer controls i f necessary. Otherwise i f measurements were made a f t e r the paper i s wound in t o r e e l s and should the water content be found to be too high, the whole r o l l would have to be dried out. On the other hand, i f the paper be found to be too dry, very l i t t l e can be done to the r o l l to remedy t h i s . The mea-surement of the moisture content i n a sheet of paper moving 5 at a speed of 1500 feet per minute or more through a modern paper machine,is, however, not a simple procedure. Because the d i e l e c t r i c constant of water i s very high compared to that of c e l l u l o s e , the main objeet of t h i s thesis i s to show that the d i s s i p a t i o n factor of paper oan be used f o r the rapid measurement of the moisture content i n the high speed moving sheet. As the p r i n c i p l e of t h i s method depends mainly upon the d i e l e c t r i c losses i n the paper, a b r i e f review of the fundamental concept of d i e l e c t r i c losses Of ft condenser i s outlined, then the basic test c i r c u i t i s described and a mathematical analysis i s given. Ho determine the moat suitable frequency, tests were made with a Boonton S-Meter, type 160-A, at di f f e r e n t f r e -quencies ranging from 150 Kc. to 5 Mo. From measurements made on samples of newsprint standing s t i l l between a p a i r of con-denser plates i n a humidity chamber, experimental data were collected, tabulated, and plotted on graphs. F i n a l l y to i n -vestigate what ef f e c t the speed of paper had on.the Q-Meter readings, measurements were made on a sample disc of newsprint spinning up to a speed of 1800 feet per minute between a set of semi-circular plates. 6 I I REVIEW OF LITERATURE The p r i n c i p l e s of suseeptanee-variation, frequency-v a r i a t i o n , or voltage-comparison i n resonant c i r c u i t s have been used i n the determination of the power factor and the d i e l e c t r i c constant of i n s u l a t i n g materials. Hartshorn and Ward (12)* made use of capacitance-variation i n a tuned c i r c u i t with a vacuum-tube voltmeter as a resonance detector to measure the p e r m i t t i v i t y and power factor of i n s u l a t i n g materials over a range from 10 k i l o c y c l e s to 100 megacycles. Adjustments are made by means of two micrometer condensers. Both the p e r m i t t i v i t y and power factor are obtained as the r a t i o of capacitance readings. Yager (23) used an external condenser connected i n p a r a l l e l with the-internal tuning*-,' condenser of a Boonton 0-Meter, type 100-A, to measure the frequency v a r i a t i o n of the d i e l e c t r i c constant and d i e l e c t r i c l o s s factor of various p l a s t i c s over a frequency range from 100 k i l o c y c l e s to 3 . 5 megacycles. Wood (22) recently i n England measured the moisture content of a sheet of c l o t h moving between a p a i r of condenser pl&tes. The Q of t h i s condenser i s measured and compared with the Q. of a calibrat e d c i r c u i t , and any differences are used f o r control purposes. Except for higher speeds, the problemi of moisture mea-surement i n paper m i l l s i s about the same as that i n the ? Cited. *A11 numbered references are given i n l i t e r a t u r e 7 t e x t i l e m i l l s , and hence i t should be feasible to apply the Q-meter f o r measuring moisture i n paper m i l l s . Extensive researches have been carried out on the measurements of d i e l e c t r i c constant, power fa c t o r , and d i -e l e c t r i c losses of i n s u l a t i n g materials. I t i s well-known that adsorption of moisture by any i n s u l a t i n g material causes a large increase i n i t s direct-current conductivity and i n the power loss dissipated under a l t e r n a t i n g voltage, liibben (11) investigated i n great d e t a i l , the v a r i a t i o n of capacity, t&nd (where 6 i s the loss angle of the d i e l e c t r i c ) , and the d.c. conductivity with percentage moisture content for telephone-cable paper. As shown i n Figure 1, the increase of tancf, and hence the power los s , becomes more rapid as the moisture content i s above 4$. Minton (15) investigating the v a r i a t i o n Paper (3 Samples) Iiubben. tan6 0 0 5 0 0.020 O.0/O 0005 0002 0 / 2 3 ^ 0 - 6 7 8 9 % Moisture Confcaf F i g . 1 of percentage power factor with percentage moisture content fo r pressboard found a s i m i l a r r e s u l t . A d i e l e c t r i c by ordinary electromagnetic theory i s J / 1 • Log rur 1 o -8 characterized generally by i t s two constants: ( i ) i t s d i -e l e c t r i c constant and ( i i ) i t s conductivity. A c t u a l l y , how-ever, the behavior of d i e l e c t r i c s i s found (11) to be not s o l e l y determined by these two constants because a l l s o l i d and l i q u i d d i e l e c t r i c s show c e r t a i n properties which seem to be quite independent of them. These properties are usually c a l l e d t h e i r anomalous or abnormal properties and the most important of these anomalies i s the power loss occurring i n an a l t e r n a t i n g f i e l d . Many theories have been suggested to explain these anomalous properties of d i e l e c t r i o s . Among the more well-known ones are Maxwell's Theory of the layer D i e l e c t r i c (16), ( E l ) , and Debye's Dipole Theory (11). Maxwell started with the assumption that a l l d i e l e c t r i c s have both the ordinary d i e l e c t r i c constant and conductivity, and that under an e l e c t r i c force they function simultaneously and independently of each other. For s i m p l i c i t y he assumed that a d i e l e c t r i c i s b u i l t up of a number of plane s t r a t a of d i f f e r e n t materials, and stated that a medium formed of a conglomeration of small pieces of d i f f e r e n t materials would behave i n the same way. This l a t t e r statement, however, was not supported by further analysis. By t h i s theory, i t i s assumed that wvery d i e l e c t r i c which shows absorption consists of a mixture of two or more d i f f e r e n t materials even though i t may appear to be homogeneous under the closest examination. The d i f f e r e n t values of the d i e l e c t r i c constant and conducti-v i t y i n the successive layers of Maxwell's layer eondenser fire used to account for the r e l a t i v e l y long time necessary f o r 9 complete charge and discharge of a condenser. Debye assumed that the molecules of some materials are not symmetrical and that they therefore possess permanent e l e c t r i c moments. When such materials are placed i n an e l e c t r i c f i e l d , the molecules are rotated so as to bring t h e i r axes i n alignment with the f i e l d . I f the molecules are free to rotate, they assume a de f i n i t e orientation to constitute a p o l a r i z a t i o n of the material. The d i e l e c t r i c constant of the material i s increased by such orientations of the polar molecules. I t i s probable that the r o t a t i o n of the molecules of l i q u i d s and s o l i d s are opposed by f r i c t i o n a l forces depending on the v i s c o s i t y of the material. The effect of these forces w i l l be to retard the p o l a r i z a t i o n due to the polar molecules and thereby gives r i s e to the phenomenon of d i e l e c t r i c absorption and power loss i n a l t e r n a t i n g f i e l d s . 10 I I I SURVEY OF EXISTING METHODS OF MEASUREMENTS Ever since paper waa f i r s t made on a mass production basis, a r e a l need for a simple and instantaneous measurement of moisture content of the moving sheet has confronted m i l l operators. To date, the only r e l i a b l e method commonly used i n Canadian paper m i l l s to measure moisture content i s by the weighing of a paper sample before and a f t e r drying i n an oven. The standard technique of t h i s periodic sampling i s s p e c i f i e d i n TAPPI Standard T-412-m^42. There i s no doubt of the high degree of accuracy of t h i s oven method, but i t has the b i g disadvantage of time lag to the extent of several hours. During t h i s time lag, many reels of paper are wound up before any adjustments can be made, i f necessary. Moreover, conditions may have changed within t h i s time lag. Hence to overcome t h i s disadvantage, the moisture content of the moving sheet must be measured d i r e c t l y and rapidly to give instantaneous readings. Some methods have been devised u t i l i z i n g such mea-surable c h a r a c t e r i s t i c s of the sheet as r e s i s t i v i t y , humidity, temperature, tension, and work done by the sheet f o r an i n d i -cation of the moisture contained. One method (3) uses a sensitive s t r i p of cellophane i n a box stretched across the paper machine so that the web of the paper runs over an open face of t h i s box. The vapour from the sheet w i l l e i t h e r lengthen or shorten the sensitive cellophane s t r i p , to oper-ate a re l a y that controls the dryer temperature accordingly. 11 In another method commonly used (3), a l i g h t r o l l e r suspended from hinged arms ride s on the sheet i n the space between two dryers. When the sheet i s damp, i t w i l l sag under the weight of the r o l l e r s to move the arms. This movementtwhich i s pro-portional to the dampness of the sheet, i s used to control the dryer steam pressure. I t was found that t h i s method kept the moisture i n the sheet at a uniformity that i s better than the pr e c i s i o n of most moisture t e s t s at the dry end of the machine• Of the e l e c t r i c a l systems devised to date f o r mois-ture measurement on paper machines, none seems to have won general acceptance i n industry. The Yerigraph made by the Foxborq Company of Poxboro, Massachuettes, U.S.A. e s s e n t i a l l y measures the humidity of the moving sheet with a h a i r hygro-meter enclosed i n a shoe that i s r e s t i n g on the sheet. A l -though i t has been i n s t a l l e d i n a few m i l l s i n Canada, the Verigraph i s not i n use because of d i f f i c u l t i e s i n getting the e l e c t r i c a l c i r c u i t s to function properly. Another i s the Brown Moist-O-Sraph (5) made by the Brown Instrument Company of Chicago, U.S.A. This instrument uses a Wheats tone bridge to measure the resistance of the moving sheet between two r o l l e r s . I t s operation i s based on the relationship between the moisture content and the e l e c t r i c a l conductivity of the paper sheet. According to a June, 1948 report (18), t h i s instrument has been tested i n the l a s t ten years under a c t u a l production conditions. These f i e l d tests proved the a b i l i t y of the Moist-O-Graph to operate successfully i n m i l l s pro-IE dueing a variety o^ papers including newsprint. Tests showed that variations i n machine speed, mechanical draw, machine vent i la t ion, furnish, cal iper , and sheet formation do not affect the ca l ibra t ion. However, i t was found that changes i n the type of dye used or i n the pH of the stook do affect the ca l ibra t ion . This shift i n cal ibrat ion i s said to be so small that the instrument readings remain accurate and r e l i -able within the l imi ts of sampling as long as the changes i n dye and pH do not exceed those which can be tolerated i n the manufacture of a given type of paper. In other words, to pro-duce a noticeable effect i n the instrument ca l ibra t ion, i t i s claimed a change i n the dye or the pH must be of such ampli-tude that the quality of the finished products w i l l be s e r i -ously affected and w i l l be readi ly noticeable to the machine tender. The biggest factor, though not mentioned i n the above report, should be variations of cal ibrat ion due to temperature changes which are inherent i n a l l r e s i s t i v i t y measurements. Because of these cal ibrat ion shifts due to one or more v a r i -ables, some m i l l operators have an aversion to the r e s i s t i v i t y method. According to the January, 1949 Monthly Report of th» Applied Science Div is ion , Powell River Company (10), experiments are being conducted on an electrostat ic dryness indicator using the varying length of glow i n a special ly made gas discharge lamp to indicate the amount of moisture i n the sheet. Although the experiments were qual i ta t ively sa t i s -factory, the proper glow-discharge lamp has not yet been made. 13 Perhaps due to lack of a more re l iable and quick sc ien t i f i c method, i t i s common i n the mi l l s today for an operator to test the moisture content i n a moving sheet by feeling the top of the paper with an open hand. This method i s , of course, subjeet to human limitations that vary with the judgments of different individuals . Moreover, with no indicating device to guide them, the operators tend to over-dry the sheet since an overdried sheet i s not nearly so notice-able as one that i s running on the moist side. This i s the c r i te r ion machine operators used to produce an acceptable sheet, but the consistent production of overdried paper i s a detriment to both m i l l economy and paper qual i ty. Newsprint containing less moisture must contain more cellulose per ton so that for each eord of wood processed less paper i s being made than i s prac t ica l ly possible. In addition, the overdried paper i s of infer ior quality to that containing the proper amount of moisture. To be accepted generally by the m i l l s , any new moisture content measuring device must overcome a l l limitac-tions inherent i n the principles and methods used such as low degree of accuracy, slowness in response, or i t icalness to variables, and dependence on individual judgment. It i s believed that the dissipat ion factor method investigated i n this thesis can give a rapid and accurate indication of the moisture content by measurement of d ie lec t r i c losses with a Q-meter which i s a laboratory instrument developed only a few years ago. This method has also the advantage that no contaet 14 with, the paper i s necessary. Furthermore, no specia l ly-trained or h igh ly-sk i l l ed technician i s required to operate the Q-meter i n this dissipation factor method. 15 IV INVESTIGATION A. THEORY OF MEASUREMENT Composition and D i e l e c t r i c Constant of Paper Fundamentally, paper may be defined as an aqueous deposit of c e l l u l o s e . The pulp stock i s a suspension of minute cellul o s e f i b e r s i n water which acts as a c a r r i e r to deposit these f i b e r s onto a wire screen. The water i n the cellulose deposit i s successively removed i n the following steps: draining, applying suction from the under side of the screen, pressing the newly formed sheet between r o l l s , and f i n a l l y passing the sheet through a. series of dryer r o l l s that are heated i n t e r n -a l l y by, l i v e stdam. Hence the general function of a paper machine i s to reduce the water content of t h i s pulp mass and smooth i t out evenly to form a sheet. For newsprint, the amount of water removed i s from 95% at the wet end down to around 6 or 7% at the dry end of the machine. The d i e l e c t r i c constant i n paper i s found to be a variable depending upon the moisture content. At a low moisture content, the value of d i e l e c t r i c constant (3) i s only around 25 instead of i t s normal value of 80 fo r l i q u i d water. The explanation given by Hartshorn and Wilson (13) i s that the high d i e l e c t r i c constant of water i n the l i q u i d state i s almost e n t i r e l y due to 16 the orientation of i t s polar molecules i n an e lec t r ic f i e l d . The rotation of molecules forming the top layer of an adsorbing surface i s severely l imited because they are strongly held to the surface. In the successive layers underneath, the molecules are less and less secure-ly held so that the ease for greater changes of orienta-t ion increases with each layer u n t i l such a depth at which the molecules have the same freedom as those i n the l iqu id form. Ideal Condenser C i r cu i t . F i g . £: Consider the case of an idea l condenser con-s i s t ing of two plates separated by a i r and connected to an alternating sine-wave generator, as shown i n Figure £. The condenser, C^, w i l l alternately charge and discharge for each cycle. During the charging half of the cycle, when the voltage across C^ i s increasing, energy w i l l be received from the generator. During the other hal f of the cycle, when the voltage across C^ i s decreasing, the condenser w i l l discharge and return energy to the gener-ator. I f a l l the energy required to charge the condenser i s completely returned to the generator on discharge so that none i s consumed i n the process, the condenser has a zero power factor. 17 3. Ideal Resistor C i rcu i t . T F i g . 3 Figure 3 shows the case of the perfect res is tor , l o e l ec t r i c a l energy can be stored so that the energy absorbed by R i must be completely dissipated. This perfect resistor has a unity power factor, and the current i s i n time phase with the voltage. 4. Imperfect-Condenser C i r cu i t . W///M F i g . 4 Uow consider the ease when the space between the ideal-condenser plates i s f i l l e d with d ie lec t r ic other than a i r as shown i n Figure 4 . The condenser w i l l charge and discharge as before but the d ie lec t r ic w i l l dissipate some of the energy absorbed. This dissipat ion of energy i s caused, i n general, by two independent processes: ( i ) losses due to conduction of e l e c t r i c a l charges. ( i i ) losses associated with the vibrations or movements of atoms and molecules. 1 8 Equivalent Circui t for Imperfect-Condenser. Regardless of what process by which energy i s dissipated, the results oan he obtained by a study of the equivalent c i r c u i t . For analysis, the imperfect condenser may be replaced by an equivalent idea l or lossless con-denser shunted by a resistance of conductance, Rp, as shown i n Figure 5. In this equivalent c i r c u i t , C , the capacitance of the ideal condenser i s equal to 6 times that of the d i e l e c t r i c - f i l l e d one of Figure 4, where £ i s the d ie lec t r ic constant of the insulat ing material. The resistance i s of such a value that the same amount of energy w i l l be. dissipated i n this c i r cu i t as that of Figure 4. F i g . 5 The current vector diagram of this equivalent pa ra l l e l c i r cu i t i s shown i n Figure 6 . c J« F i g . 6 where: 0 s phase angle, 6= 9 O ° - 0 - loss angle. *p = current i n the condenser branch su>CE=Ieosd I R B current i n the resistance branch=jE_ - I s i n d I s t o ta l current = 1Q - I R . I 19 The d ie lec t r ic loss = W = EI sincf r E s in 6 mCE eostf = EwC tano It i s convenient to have the general re la t ion-ship between the components of the equivalent pa r a l l e l and series c i r cu i t s shown i n F i g . 7, where H s and 0 S are the series components, R p and Cp are the pa r a l l e l components. /VW^-(I ^WV^ enes Parol lei F i g . 7 Equate the current drawn by each c i r c u i t : I = E - E = E Rp ^ B s - JZ S Rationalizing: E__ - _E_ : . ER S % J X P R* + xg Equating the rea l and imaginary teims: r2 EXg JCHJ t Z§) R p = R a (1 + Z | ) - H 8 ( 1 + Q2) = R s ( l + 1 ) I f Z- = Z g ( l + R§) - Z Q ( l + 1 ) : X g d r D 2 ) i f ^ where Qi = Z g , and D = 1 - dissipat ion factor R s Dividing: R^ = RaQ = R s .1^ Z, s Z s D' •'• Q = l = Z s = R p Hence the Qi for a pa ra l l e l c i r cu i t i s the ra t io of i t s resistance to i t s reactance. 2 . 0 B . D E S C R I P T I O N Q P T E S T C I R C U I T A H D A P P A R A T U S • Test Circui t and Analysis* Basica l ly the test c i r cu i t i s shown schemati-ca l l y i n Figure 8. , L R, c T T :«, ® F , I G . 8 , where: 1 = inductance of the external inductor. R L z resistance of the external inductor. 9A = o&.paei"tiQS of the main and venier tuning condensers of the Q-meter. C B S capacity of the test condenser, externally connected. R B s resistance of the test condenser externally connected. E ^ z fcnown value of input voltage from the o s c i l l a t o r . V c r vtvm reading of the voltage across the condensers. 21 To find the Q of the test condenser (Q^) F i r s t consider the c i r cu i t when the test condenser assembly i s not connected. This simplif ies the basic c i r cu i t of Figure 8 to that of Figure "9„ /TPPPT /ww-F i g . 9 where C 0 = capacity at resonance. JLt resonance o>2L = JL, '0 E L U J C Q R L (1) (2) Next consider the' c i r c u i t with the test condenser assembly connected as shown i n Figure 10, —nswp—/WA © c F i g . IP where G r s capacity to resonaite c i r cu i t with the test condenser connected, le t Z-£ - impedance of the test condenser - ~ &t*t (3) 22 l e t Zp r equivalent p a r a l l e l impedance of G r and Z^ . Z rZt „ T _ i Z r + Zt where Z ; -JX r, Xj. -(-jX r) - W t - 3 * t R t Ht * J'xt = XyXt + ii-Rfy + ^ X y ) R a t i o n a l i z i n g (4) 2p = X ^ 2 + R|(X t + Xj.) 2 = R e - dx, e where R e = x|xf + R|(X t • X r) 2 UJC, (4) (5) (6) (7) *e = y ^ t ^ t » £ r ) " xfxf + R | ( X . + X J , ) 2 (8) Then the c i r c u i t s i m p l i f i e s to Figure 11* •^RW ^ F i g . 11 23 JLt resonance wl* - Z e then Qa B w L 3 ~ Bi+ a e = 1 He 1 Z. _ + Q 0 R t ( Z t + Z r) Hence Q _ Q 0R t(Z t * Zr) R t t Z t + Z r; + ^ Z t Z j . Solving for R t R t - V W ^ t z t + Zj, where m - Q0Q8 Solving f o r Z t 3 <5 Ze = " *Er«r 2 m^Z^ yr ( Z t + Z y J d + nT) 24 then Z t z VT^1 + M > - Z e ( l + m2) + m 2 (Z r ) -z e + z r U 2 + i i f m i s very large, then 1 ^ £ 2 * - 1 m l 1 t (17) 2- 1 (18) .'. Z+ - "^e2^ (19) * ~ ~*e + *r Putting Z e -uiL = wcr then 1 , X^,. " Z - ^ o ^ r t ~ ^ 1 + 1 UJG"£.. uuCr 1 1 (20) = m-uuOr -u)Cr + uuG, M*. 1 , (21) Q 0 - Q s U J C 0 25 then hy Ever i t t ( 6 ) p. 81 for a pa ra l l e l c i r cu i t Q t =  X z t = <*oQ« . 1 . 1 W i 0 o - c r j = M a ( c o " c r ) , (S2) 26 Q-Meter Theory. B a s i c a l l y , a Q-Meter i s composed of three main u n i t s : (a) an o s c i l l a t o r , (b) a measuring c i r c u i t , and (c) a coupling for the o s c i l l a t o r to the measuring c i r c u i t . This fundamental c i r c u i t i s shown schematically i n Figure 12., . OSCILLATOR F i g . 12 A calibrated voltage, B i t i s supplied from the o s c i l l a t o r to the series c i r c u i t by passing a measured current through the low resistance, E. A shielded trans-mission l i n e terminating i n a thermocouple and at 0.04 ohm non-inductive r e s i s t o r are used as the means of coupling. The measuring c i r c u i t consists of main and vernier tuning condensers together with a vacuum-tube voltmeter which measures the voltage developed across the conden-sers. When a c o i l i s connected to the external c o i l -terminals, A and B, the series c i r c u i t i s tuned to re-sonance as indicated by a maximum d e f l e c t i o n of the Q-voltmeter to give the Q of the c i r c u i t . 27 The c i r c u i t can be further s i m p l i f i e d as shown i n Figure 13 for mathematical analysis. L RL where F i g . 13 1 - inductance of the external inductor. Rj = resistance of the external inductor. CA - capacitance of the tuning condensers. R Q z resistance of the tuning condensers. At resonance, the reactances are equal. *L • xo The voltage across C i s given by v c = ¥ c z f t H i + R 0 0 S i ; Jo 21 X a L t l Qi Qc 28 In most c i r c u i t s , the resistance of the con-denser: i s ? ne g l i g i b l e compared to that of the inductor so that Q 0 > » Qj,. ThJis the voltage across the con-denser i s equal to the product of the injected voltage times the e f f e c t i v e Q of the resonant c i r c u i t , hence V Q s Since the injected voltage, Bj_, i s of a fcnown value, the voltage across the condenser, Y 0, may be c a l i -brated i n terms of and the ammeter, M, may be c a l i -brated as a m u l t i p l i e r of the ^-voltmeter readings. A front view of the Boonton Q-Meter type 160-A i s shown i n photograph #3 and the schematic c i r c u i t diagram i s shown i n photograph #4 i n the Appendix. 29 Teat Condenser Assembly and Humidity Chamber. The test condenser consisted of two c i r c u l a r Dural plates, 3 inches i n diameter and inch t h i c k . Each plate i s fastened to the end of a 5 inch diameter 8 polystyrene rod with a countersunk flathead screw at the centre of the plate. Through snuggly-fitted holes i n bakelite panels mounted on each side of the chamber, each polystyrene rod can be adjusted so that the distance be-tween the plates may be varied. The lead-in connections to the plates are made at the bottom with banana-plugs inserted i n a inch polystyrene panel f o r low losses* The entire humidity chamber i s constructed of wood and i s painted with several coats of enamel paint. For observation the door i s made of •% inch t h i c k l u c i t e . A chemical balance i s mounted over the top of the chamber and a thin thread attached to the bottom of one pan i s dropped through a small hole at the top of the chamber. The paper sample i s suspended f r e e l y between the two condenser plates by t h i s thread. To obtain a c e r t a i n humidity, two pans of a saturated chemical sol u t i o n are placed inside the chamber. This whole experimental arrangement i s shown i n Figure 14. Test Conc/eoser Plate Luc/te \y Door • Sa/ar<zfec( 31 4. Teat Assembly for E f f e o t of Speed of Paper. For t h i s t e s t , the c i r c u l a r Dural Condenser plates were replaced by two U-shaped pieces of 3 inch 8 thick brass as shown i n Figure 15.. These plates were designed i n this shape so that the peripheral speed of the paper passing between the outer and inner r a d i i of the plates would be about the same. The test newsprint samples are cut into 6-inch diameter discs with a small hole i n the centre f o r clamping onto a 3 inch diameter d r i l l rod which runs between b a l l bearings mounted at eash side of the chamber. An e l e c t r i c motor mounted at the top of the chamber drives the d r i l l rod through a b e l t and pulleys. By varying the voltage input to the motor with a 1-ampere General Radio variac, any desired speed of the paper from s t a n d s t i l l to f i v e or s i x thou-sand feet per minute may be obtained. This test assembly i s shown conneoted to the Q-meter i n photographs #1 and #£. 3_« 32 F i g . 15 8 02 • 0 * 0 Photograph fl -showing, the Humidity Ghaiaber Assembly for Speed Tests, the Type 160-A Q-Meter, and the Type 103-A Inductors. 23 Photograph #2 showing a c l o s e - u p view of the Humidity Chamber connected to the 4-Meter. 34 C. EXPERIMENTAL BE SUITS 1. Procedure. (a) Stationary Tests For the stationary newsprint tests, a 6" hy 91* sample of 32 l b . newsprint* was suspended by the thread between the Dural plates which were set 1_ inch apart. 32 The two pans of a saturated solution were placed i n the chamber overnight. Next day, the lead-in connections from the test condenser plates were connected to the Q-meter and the suitable Type 103-A Inductor for that particular frequency band was plugged into the Q-meter. After the Q-meter was warmed up, the Q-multiplier meter was adjusted to read 1 and the Q-meter was tuned to reson-ance with the capacity d i a l . Readings were taken of the Q and the capacity. By varying the frequency from 150 ki locycles to 5 megacycles and changing the Inductor for the different frequency bands, readings of Q and the capacity were taken at each frequency. F ina l ly , the paper was weighed with the chemical balance. For the second part of the tests, the paper sample was removed and the. whole set of Q and capacity readings was repeated at each frequency. *The 32 lb , newsprint specification means that 500 sheets, size 24" by 36", weigh 32 lbs . 35 In t h i s i n v e s t i g a t i o n , readings were taken at three d i f f e r e n t conditions of moisture content and the following saturated solutions were used to obtain these d i f f e r e n t humidities: ( i ) 6.45$ moisture content - no so l u t i o n used. ( i i ) 11.6$ moisture content - Ca(N0g)2,4Hg0 so l u t i o n . ( i i i ) &0.6$ moisture content - NagSO^*lOHgD so l u t i o n . (b) Speed Tests The paper discs were clamped onto the d r i l l rod with bakelite flanges and the set screws tightened. The semi-circular brass condenser plates were brought together to about 1 inch apart. By checking the speed 16 of the disc with a Strobotac, the required speed was obtained by adjustment of the variac. Readings: were taken of Q: and C when the disc was r o t a t i n g at 1100 feet per minute, 1850 feet per minute, and at s t a n d s t i l l . The disc had to be removed from the chamber and weighed i n the balance. This i s not a very accurate method but as the primary object i s ; to determine the effect of speed, an approximate percentage moisture content i s s u f f i c i e n t . 36 Observations fa) Data of Stationary Tests The r e s u l t s of the testa at the various moisture content are tabulated i n the following tables: ( i ) Table I - at 6.45% moisture content. ( i i ) Table I I - at 11.6% moisture content. ( i i i ) Table I I I - at 20.6% moisture content. Then the values of the Q of the paper sample, (O^) are calculated from the following formula: ^ = M i l V l J l ' where: s Q. of the c i r c u i t without paper d i e l e c t r i c . s Capacity of test condenser i n uuf without paper d i e l e c t r i c . - Q of the c i r c u i t with paper d i e l e c t r i c . Cg Capacity of t e s t condenser i n uuf with paper d i e l e c t r i c . C Q s Capacity i n uuf to resonate the inductor alone. These values of are tabulated i n Table IV and plotted graphically i n Figures 16 to*21. (b) Data of Speed Tests A l l the r e s u l t s of these tests are tabulated i n Table V. 37 TAB IS I Q-Meter Headings of Test on Newsprint Sample of 6.45$ Moisture Content INDUCTOR FREQ. Without Newsprint With Newsprint TYPE 103-1 Ql Dl C l Q2 »2 c2 No. 32 150 Kc. 165 360 90 155 348 102 200 Kc. 177 167 86.5 158 156 97.5 250 Kc. 176 76 87 146 64.5 98.5 No. 31 300 Kc. 194 196 86 171 184 98 350 Kc. 191 124 82 161 112.5 93.5 400 Kc. 185 73 86 149 62 97 No. 22 500 Kc. 171 320 85 158 309 96 600 Kc. 189 200 83 165 . 188.5 94.5 700 Kc. 200 125 82 165 114 93 800 Kc. 207 76 83 159 65 94 No. E l 900 Kc. 187 232 80.5 164 218 94.5 1000 Kc. 195 174 80 163 160 94 1100 Kc. 199 129 80 160 116 93 1200 Kc. 201 94 81.5 155 81.5 94 No. 12 1.5 Mc. 170 366 84 156 355 95 2.0 Mc. 190 171 82.5 157 160 93.5 2.5 Mc. 201 79 83 145 67 95 No. 5 3.5 Mc. 194 331 80 166 317 94 4.0 Mc. 200 234 84 161 220 98 4.5 Mc. 20E 164 87 153 151 100 5.0 Mc. 206 116 86 144 103 99 Where: Ql s Q: of the c i r cu i t without paper d i e l ec t r i c . Dl s Capacitor-dial reading i n uuf without paper d i e l ec t r i c . C l s Capacity of test condenser i n uuf without paper d i e l ec t r i c . s (C 0 - D i ) . 0 C t f s Capacity i n uuf to resonate the inductor alone. Qg s Q of the c i r c u i t with paper d i e l ec t r i c . DJ2 = Capacitor-dial reading i n uuf with paper d i e l ec t r i c . Cg s Capacity of test condenser i n uuf with paper d i e l ec t r i c . * ( C 0 - Dg). 38 UBIE I I Q-Meter Headings of Test on Newsprint Sample of 11.6$ Moisture Content INDUCTOR FREQ. Without Newsprint With Newsprint TYPE 103-A Ql *>1 C l Q 2 »2 0 2 No. 32 150 Kc. 165 359 91 145 346 104 200 Kc. 177 164 89.5 141 152 101.5 250 Kc. 176 73 • 90 126 61.5 101.5 No. 31 300 K c 195 196 86 161 183.5 98.5 350 Kc. 191 124 82 148 112 94 400 Kc. 185 73 86 136 61 98 No. 22 500 Kc. 171 320 85 152 309 96 600 Kc. 189 200 83 159 190 93 700 Kc. 200 128 79 156 118 89 800 Kc. 207 76 83 150 66.5 92.5 No. 21 900 Kc. 185 233 79.5 162 223 89.6 1000 Kc. 195 174 80 163 164 90 1100 Kc. 199 132 77 160 122.5 86.5 1200 Kc. 201 95 80.5 155 86 89.5 No. 12 1.5 Mc. 170 366 84 154 356 94 2.0 Mc. 190 170 83.5 156 160 93.5 2.5 Mc. . 201 79.5 82.5 143 69 93 No. 5 3.5 Mc. 193 330 81 164 319 92 4.0 Mc. 199 235 83 159 225 93 4.5 Mc. 202 164 87 152 155 96 5.0 Mc, 206 122 80 140 112 90 Where: Ql = Q of the c i r cu i t without paper d i e l ec t r i c . Di - Capacitor-dial reading i n uuf without paper d i e l ec t r i c . C]_ - Capacity of test condenser i n uuf without paper d i e l ec t r i c . = ( C 0 - D L ) . C 0 - Capacity i n uuf to resonate the inductor alone. Qg = Q of the c i r c u i t with paper d i e l ec t r i c . D 2 = Capacitor-dial reading i n uuf with paper d i e l ec t r i c . ^2 = Capacity of test condenser i n uuf with paper d i e l ec t r i c . = (C 0 - Dg). 39 TAB IE I I I Q-Meter Readings: of Test on Newsprint Sample of 20.6$ Moisture Content INDUCTOR FREQ. Without Newsprint With Newsprint TYPE 103-A J>1. Ol Q2 ^2 c 2 Ho. 32 150 KG. 165 365 85 89 347 103 200 Kc. 177 170 83.5 72 154 99.5 250 Kc. 176 78 85 56 63 . 100 No. 31 300 Kc. 194 195 87 85 184 98 350 Kc. 191 121 85 72 110 96 400 Kc. 185 71 88 60 61 98 No. 22 500 Kc. 171 319 86 103 308 97 600 K c 189 200 83 94 189.5 93.5 700 Ko. 200 124 83 83 114 93 800 Kc. 207 76 83 75 67 92 No. 21 900 Kc. 185 229 83.5 103 218 94.5 1000 Kc. 195 170 84 98 160 94 1100 Kc. 199 129 80 90 119.5 89.5 1200 Kc. 201 93.5 82 81 84 91.5 No. 12 1.5 Mc. 171 365 85 117.5 356 94 2.0 Mc. 190 170 83.5 99 160 93.5 2.5 Mc. 201 77.6 84.4 80 68 94 No. 5 3.5 Mc. 194 330 81 132 320 91 4.0 Mc. 200 234 84 122 224 94 4.5 Mc. 201 164 87 109 154 97 5*0 Mc. 206 115 87 98 105 97 Where D l -Co I D 2 -Q. of the c i r cu i t without paper d i e l ec t r i c . Capacitor-dial reading i n uuf without paper d i e l ec t r i c . Capaoity of test condenser i n uuf without paper d ie lec t r ic , (C 0 - D X ) . Capacity in uuf to resonate the inductor alone. Q of the c i r c u i t with paper d i e l ec t r i c . Capacitor-dial reading i n uuf with paper d i e l e c t r i c . Capacity of test condenser i n uuf with paper d i e l e c t r i c . (C 0 - D 2 h 4 0 T&BIE I V Calculated values of the Q of the newsprint sample. INDUCTOR FREQ. % TYPE 103-£ A B C No. 22 150 Kc. 68.1 34.5 7.73 200 Kc. 64.0 22.2 7.66 250 Kc. 61.3 31.2 7.55 No. 31 300 Kc. 61.4 40.9 6.50 350 Kc. 57.1 28.2 6.16 400 Kc. 53.0 25.5 5.60 No. 22 500 Kc. 56.5 37.0 7.04 600 Kc. 52.7 25.4 6.94 700 Kc. 50.1 24»4 6.85 800 Kc. 47.5 22.6 6.65 No. 21 900 Kc. 59.8 41.6 8.16 1000 KC 54.8 29.0 7.75 1100 Kc. 50.8 27.2 7.46 1200 Kc. 48.4 34.8 7.35 No. 12 1.5 Mc. 46.3 26.4 8.34 2.0 Mc. 39.5 34.4 8.14 2..5 Mc. 38.5 22.1 7.86 No. 5 3.5 Mc. 39.2 27.8 10.00 4.0 Mc. 36.4 24.8 9.85 4.5 Mc. 32.7 22.0 9.50 5.0 Mc. 30.8 21.6 9.25 Where: A B newsprint sample of 6.45$ moisture content. B - newsprint sample of 11.6$ moisture content. C = newsprint sample of 20.67« moisture content. 41 TABIE V SPEED OF PAPER TESTS c o n FREQ. SPEED TEST No.4 TEST No.5 TEST No.6 04 D 4 ^5 D5 % D 6 No. 42 50 Bo. N Q Ni No 79 Tt It 376 tt tt 75 tt tt 378 tt tt 84 it it 130 tt tt 100 Ko. N 0 Hi ?8 96 tt tt 69.2 tt • i i 96 it tt 70.9 tt it 75 tt it 70 tt tt NO. 32 150 Kc. Ni N 2 154 tt tt 418 tt tt 152 tt tt 419 tt tt 142 tt tt 418 tt tt 300 Kc. NO N i Ng 185 it it 82 tt tt 184 it tt 82.2 tt it 152 n tt 81.8 tt tt No. 22 500 Kc. N U N I 170 tt tt 376 tt it 166 it it 379 Hi tl 164 tt tt 378 it tt 1000 Kc. N 0  W l 200 it tt 73.5 it tt 193 tt tt 74.5 tt tt 172 tt ti 74 tt tt No. 21 1500 Kc. N u Ni No • 195 it it 84.2 tt tt 190 it tt 86 tt ti 174 it it 85.2 tt tt 2000 Kc. ^0 % % 170 it tt 35.5 tt it 166 tt tt 36.8 tt it 149 tt ti 36.6 tt tt No. 12 3 Mc. K 0 N l No 204 tt tt 86 it tt 199 tt it 86 n tt 186 it n 87 tt tt 4 Mc. N5 5i 194 it 36.5 tt it 184 tt it 37.2 it it 169 it tt 37.5 tt it No. 2 5 Mc. S; 4 185 tt tt 380 it tt 184 it tt 375 tt ti 184 tt ti 376 it ti Where: N 0 S» when paper i s .stationary. N^ = when paper i s moving at 1100 feet per minute. N p -= when paper i s moving at 1850 feet per minute. Test Weight i n gms. Moisture Content Q-Meter Readings Capaoity-dial Readings i n uuf. ,;io. 4 0.992 7.0% D 4 No. 5 1.006 8.5% Dfi No. 6 1.050 13.3% 4 D 6 4 2 7 DISCUSSION AND PROSPECTUS The results of this l imited investigation have shown that: (1) The moisture content of newsprint can be rapidly measured by the Q-meter with adequate accuracy* (2) The speed of the paper even up to a velocity of 1800 feet per minute between the condenser plates does not have any effect on the readings of the Q-meter. (3) The results i n the lower radio-frequency range are better than those i n the megacycle region. The slopes of the curves i n Figures 16 to 21. show that there i s sufficient variation i n the Q of the paper sample for a small change i n percentage moisture content i n the 7 to 10% moisture content range. The results i n the megacycle region may be i r r a t i c because at such high frequencies, increases i n the resistances due to skin effect and Stray .impedances i n the Q-meter affect the accuracy of the readings. As the object of this investigation i s to establish the f ea s ib i l i t y of applying the dissipation factor method for the determination of moisture content i n newsprint, these tests are of a preliminary nature and a l l were conducted i n the laboratory on one type of newsprint only. The value of the results would undoubtedly be greatly enhanced, i f f i e l d tests had been made under actual production conditions i n a m i l l 4 3 where the readings could be calibrated against those of the oven method. Exhaustive f i e l d tests over a period of months or years are necessary to compile sufficient data for a f a i r appraisal of the prac t ica l value of this method. IPurther investigations are required to determine what effect other variables have on the readings such as variations i n : ( l ) f i l l e r , (£) stock, ( 3 ) dye, ( 4 ) pH, ( 5 ) ambient temperaturei ( 6 ) thickness of,paper. Tests should also be conducted on other types of paper as wel l as newsprint. A l l these tests could best be conducted i n co-operation with interested paper m i l l s . A few other refinements are suggested as follows: (1) The size of the test condenser may be made small enough so that the moisture i n only a small area may be checked. Since the moisture content across the sheet width i s not uniform, a pair of plates may be moved across the sheet to measure the moisture content at certain spots, or else a number of test condensers may be ins ta l led at intervals across the sheet so that the spot of maximum moisture content may be detected instantly. (2) Automatic control of the dryers may be achieved by using the output qf the- Q-meter to actuate the controls through relays. ( 3 ) Once the proper range of frequencies i s determined for measuring a part icular type of paper, the Q-meter c i r -cuit may be simplif ied or modified to produce a less complicated instrument. 44 Aa there i s def ini te ly an urgent need at present for a rapid and accurate instrument for measuring the moisture content of a moving sheet of paper, further investigation :bf this dissipation factor method i s warranted. 45 VI LITERATURE CITED 1. Argue, G.H. and Maass;, 0. Measurement of the Variation of the Die lec t r ic Constant of Water with extent of Adsorption. Canadian Journal of Research, v o l . 13, section B, p. 156, 1935. 2. Brockelsby, C F . An E l e c t r i c a l Moisture Meter. Journal of Scient i f ic Instruments, v o l . 22, pp. 243-244, December, 1945. 3. Campbell, W. Boyd, Pulp and Paper Research Institute of Canada, Montreal, Canada. Letter to Mr. R.M. Brown of U.B.C. dated July 9, 1948, i n regard to information about moisture mea-surement on high speed paper machines. 4. Candee, C.N. Moisture in. Paper. Pulp and Paper Magazine of Canada, v o l . 42, No. 2, pp. 121, 122, 126, February, 1941. 5. Culver, D.C. Measurement of Moisture i n Paper by the Resistance Method. The Paper Industry and Paper World, v o l . 23, pp. 555-561, September, 1941. 6. Ever i t t , W.I. Communication Engineering. New York and London, McGraw-Hill Book Company, Inc.,1937. 7. Gardiner, S.D. Instrument to measure minute changes in specific inductive capacity of cardboard and hence to determine i t s water content. Journal of the Society of Chemical Industry, vo l . 62, pp. 75-76, May, 1943. 8. Gafton, C.G. The Drying Process i n Paper as Determined by E l e c t r i c a l Methods. Journal of the Institute .. of E l e c t r i c a l Engineers, v o l . 86, pp. 369-378, A p r i l , 1940. 9. Golding, E.W. E l e c t r i c a l Measurements and Measuring Instruments. London, S i r Isaac Pitman and Sons, I/td., 1940. 10. Goumeniouk, G. Electrostat ic Dryness Indicator. Monthly Report of Applied Science Div is ion , Powell River'Company, Powell River, B .C . , January, 1949. 46 11. Hartshorn, X. A C r i t i c a l Resume of Recent Work on Dielectrics, Journal of the Institute of E l e c t r i c a l Engineers, v o l . 64, pp. 1152-1190, 1926. 12. Hartshorn, L. and Ward, W.H. The Measurements of the Permit t ivi ty and Power.Factor.of Dielect r ics at Frequencies from 10 to 10° cycles. Journal of the Institute of E l e c t r i c a l Engineers, v o l . 79, pp. 597-609, 1936. 13. Hartshorn J L . and Wilson, W. An E l e c t r i c a l Moisture Meter. Journal of the Institute of. E l e c t r i c a l Engineers, part 2, v o l . 92, pp. 403-412, October, 1945. 14. Jones, E .H. A Moisture Meter for Textile Materials. Journal of Scient i f ic Instruments, v o l . 17,No.3, pp. 55-62, March, 1940. 15. Minton,J.P. An Investigation of Dielect r ic Losses with the Cathode Ray Tube. Transactions of the American Institute of E l e c t r i c a l Engineers, vo l . 34, pp. 1627-1677, 1915. 16. Murnaghan, F.D. Maxwell's Theory of the layer Die l ec t r i c . Transactions of the American Institute of E l e c t r i c a l Engineers, v o l . 46, pp. 132-139, February, 1927. 17. Race, H.H. Capacitance and loss Variations with Frequency and Temperature i n Composite Insulation. Transactions of the American Institute of E l e c t r i c a l Engineers, v o l . 52, pp. 682- , June, 1933. 18. Sholl , H.A. Continuous Measurement of Sheet Moisture. Technical Association Papers, series 31, pp. 375-378, June, 1948/ Edited by MacDonald, R.G. and Bingham, R.T. , published by Technical Association of the Pulp and Paper Association, New York, N.Y. 19. Wangsgard, A.P. and Hazen, T. The Q-Meter for Dielect r ic Measurements on Polyethene and other plast ics at Frequencies up to 50 Mc. Transactions of the Electrochemical Society, v o l . 90, pp. 177-191, 1946. 20. Wheelwright, W.B. From Paper M i l l to Pressroom. Menasha, Wisconsin, George Banta Publishing Company, 1920. 47 21. Whitehead, J.B. Die lec t r ic Absorption and Theories of Dielect r ic Behavior. Journal of the American Institute of E l e c t r i c a l Engineers, vo l . 4 5 , pp. 515-524, February, 1926. 22. Wood, H. A Moisture Content Control Equipment, in Bernard Love 11 ed. Electronics and their Application i n Industry and Research, London, The P i l o t Press L t d . , 1947, Chap. IX, p. 382. 23. Yager, W.A. Die lec t r ic Constant and Die lec t r ic Loss of Plast ics as Related to their Compostion. Transactions of the Electrochemical Society, vo l . 74, pp. 112-129, 1928. 24. Boonton Radio Corporation. Instructions and Manuel of Radio Frequency Measurements. Boonton Radio Corporation, Boonton, New Jersey, U.S.A. 25. Tut t i e , W.N. The Series and P a r a l l e l Components of Impedance. The General Radio Experi-menter, v o l . 20, No. 8, January, 1946. 48 711 AOKNOWEEDGMBNT The author wishes to express his sincere appreciation to Dr. I'. Nbakes for his continual guidance and valuable suggestions i n carrying out th is investigation. 49 VIII LIST OF SYMBOLS = Capacity of test condenser without paper d i e l ec t r i c . Cg = Capacity of test condenser with paper d i e l e c t r i c . C A Z Capacities of the main and venier tuning condensers of the Q-meter. Cg s Capacity of the teat condenser. C^ = Distributed capacitance of the inductor. = Capacity of the ideal condenser. C 0 S Capacity to resonate the inductor alone. Cp - Capacity of the equivalent imperfect condenser. C r = Capacity to resonate c i reu i t with the test condenser connected. C g = Equivalent series capacitance. D - Dissipation factor. ^2. = ' Capacitor-dial reading without paper d i e l e c t r i c . Dg = Capacitor-dial reading with paper d i e l ec t r i c . E = Voltage across the equivalent imperfect condenser. E^ = Known value of input voltage from the osc i l l a to r . I : Total current drawn by the imperfect condenser. I = Current in the condenser branch of the imperfect 0 condenser. I D - Current in the resistance branch of the imperfect condenser. L z Inductance of the external inductor. TSQ s Zero speed of paper. ^1 = Speed of paper at 1100 feet per minute. Hp - Speed of paper at 1850 feet per minute. so <*1 r Q of the c i r cu i t without paper d i e l e c t r i c . Q *2 = Q of the c i r cu i t with paper d i e l ec t r i c . *c - Q, of the tuning condensers alone. «1 - Q of the external inductor alone. Q *0 = Q of tesonant c i r cu i t with test condenser not connected. Q 8 - Q of resonant c i r cu i t with test condenser connected. = GL of the test condenser alone. 9x — Q of the newsprint sample. R = 0.04 ohm non-inductive coupling res is tor . Resistance of the test condenser externally connected. R 0 Resistance of the tuning condenser. R e Equivalent resistance of the pa ra l l e l impedance. R i = Resistance of the ideal condenser. R L Resistance of the inductor. * P — Resistance of the equivalent imperfect condenser. E s = Equivalent series resistance. R t -i Resistance of the test condenser. V c vtvm reading of the voltage across the condensers. z e Equivalent reactance of the pa ra l l e l impedance. X r = Reactance of the tuning condensers. z t Reactance of the test condenser. 2p = Equivalent pa ra l l e l impedance of 2 r and Z^. Zr z Impedance of the tuning condensers. Z t = Impedance of the test condenser. ^ s Phase angle. "6* - loss angle. 51 02 if i •'  ; i ] i M i ; :. i r i M i l . , i • .H i t L n : M U .riiJ ! * T r if 5 r-jil- iii' 1 r]1 r i r i . j 1 - H i t ' -M n 4i Li , . |.. x ; _i'H -l-n-f-xtFI-•j-ffi-"Pl -p::: - -r 4- -H H T # " X l " X — n X " if Liijx- XL ; ; ; ! | i ; i ; ; n : i ; H i I X j 1 • [ !: :T ; 1 . . *4 : r: F.: I iX-:x XX .FrX T H + xtr * T I -X I ' •: f r X t -n ! -FX-XFT- FX X'M X I . -J- L . TV:} . . . . ::: i - • • i • • • : i R ' ' 1. • ft ' :!'.' • • -r - i ;I]H XX ,;"F:r Fi4 1-lL 1 " : •:-r-ii- -H-rr XP--1H- -.bj-i x ; ; t -H !-L • • ; -* . J , . . . 1 . |;;T !' 1X. X" T ; ::: T HH Mr. 1 ; • L ; i n i i. : i H 1 :"x ;_;r • X -L-U l—l-L l - i 1 x ; i i l l : X - ; r l!x M 1 - f: P i - X t x i ii x l x t . x r p jtiixxp XUtXlr^ X ^ r WM I J j. U iX! •flH- : i Ft -r:.L !! i: *"M; ;; .t • X X t "n -1- \ \ M f x XX -I _ .-!_ t!r !-Li 1 x ! l~X r 1 ; X .. 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M M .."i-Mr ' H-1 L x x xfi; Fi.M: -XL .Ltrt - , 1 p|. 14, . ., , .!-X X H r L X X F X • 1 1 • TLX i-ft-J . .. Pi! •11;.: - rF f | X i -1 : rr " L p l ;TJ i • • - P t -• \ itt X : " X X rn r .Mix i .xx . . . . . X : U ±::p M X p j l i M l :i:q-; 1+!'!: p i t H x t x x x x -t-i..; j -H. •H-: i :rn h::!" "rp"- XXq X ru r : X 1 LilL lT;l" X I XL -\* • \ X i -\; r f • Si\H TX-1' -H4 - ;"• i-.,. 11. .LL: -!' -;Xf-i-T1J.LT -\! i-r X-i U X t -UP-DrJt-. • 1 X ; ! x x - L X f jXLiS? •{-!-;-;• Tgji 1.1.''. j.,... u i ! I: 'f-l 7 l x ; " H i ! ' f: r " • -_T : i"j x i rX .-. : *! " ™ ' \ \ TlX'." X * 'Mxi- 31 ;•; ixf 1" T . . : J . -XX r-:ir: .iXt.i-i - U . ( r i X r i X r X H X X XFI : i M x r rr xxh i • •' V < ' • • r* :ixi t i l : .1.1.1.. !T : 1 'LX -iX X ; -v A V: !• 1 . _L XX-LX -Hj! .:..! T ; xjL L : l l I p i . xiri- I.IT . MX- : ! . x x ! L X L 1 X i p L x j X L !rH X i T J . •Mi :!tji : M^i" i i- . j : : : x.. H i :: M- ; X | v | I Li. L Xi:i xX"L X L "h'T iXf X X - H r - n X X L ^ LjJj:ii4t it ..... t., . ^ .i •v-:; "TT.I. : Hr .'0 X r f:: L- X:L i r:; HXH\ W - -: p t ! X L + H : : i X i ; U-i 1 Xt-i m .14 P.J 4 - 4 + -. L l . . _ i F L i x x x L X r xptxxii X f f i X fr - i p-j- •i- i i ; ; j Li H : i 1 :iL u i V i r"' X X " x • IMMI X f . MM".. : i ; 1. xpj: -! Ft F HrP xiix 1 : ' Xf.n. i H-t-i|jX|^ rjFI xLXrL J j X x T L ; Tf V i-M' :r; i i r : # j - :X X : ;,*H ix : l-X i X : M// I.MS;L ...I.— I P L T"--i- L ; ! - X ; i l f i ® feix; ' • L: J X - . -iltxl. X X X X L r.' ; • r . i ; r X '. 1 'Ml -.it * •}-x x ; : r:: . LnliS sxx ; X Ipi: l E p :-PL -t-U-4 MM IFF!: j l i i^ f :rTXX;:;[ ± t | i : :pxx-x.qxrxjx -fl- M--i-tij "{'.1';. pi ;• ; - i r " Li" ; . i .ri':: I'M -ni X: r •;:: r X X H i i -: H :• FX L X "H ;pr XX-: -LFF ti-!. [--!JT;. JL;XI X I ] X L L F 0 X ! -f r H X H 4 - +hT L ; i Mi I'M :": r ; : r . L i H' r' HH Mi H:: X : X r : : : : Xl",. X i Hi ri-X x;: I H i : "1 X i IF. -' P t T . LIT" n X L L X L - H rxp -tjxf -U l- t +:-H X-!. H - r X v * '' :'. n .-•LH r . n M'ML :.ri.: : X :: x H i ! :::! . . X- X r - • I TX 1 L L 1 . . 'IX; X L X x - X nx HL XFtilX M XC •:: i u : • j • • : i r t ;M ..: .-.-Mi y/ .... L I 5 X mi y/M/ X n j r M . x X •.'.•i± 'f-ft |'F" I X iiil : ft tl X •-H- . . u : ; .Ml: i l L i ' H Perce ;M< eX Johte itMHH . . . 1 . , . , T i X L L X T jxp xti': t M x tt!:|lf:i]-:.p;f p : r i .' ; i : 17-. i-i'8 rax agi. an? th 3 - r e l .. 1 at ion the J? ?hi P an- ith ibi; B.t Xo' h« :!:: r M X L X T h x ^ i i x x S f x % XLuL_i.-U4 1 ; ' 1 ' T l t 1 : 1 lip - ; , i £ pr '1(3 .aha.. arc ^ X - SageH 1T€ 0 Wjj i i i x l i 53 54 56 57 X APPENDIX • Photographs #3 and #4 are eopied from the "Instructions and Manual of Hadio Frequency Measurement", Boonton Radio Corporation, Boonton, lew Jersey, U.S.A. Photograph f3 ILLUSTRATING THE IMPORTANT FEATURES IN THE OPERATION A N D CONSTRUCTION OF THE TYPE 160-A Q-METER 17 27 9 6 7 8 l i l M 17 16 26 27 W 9 13 14 12 Fig. 4 DESCRIPTION OF PARTS 1 Oscillator Output Control. 2 Osc. Out. VM. (Mult. Q By Meter). 3 Oscillator Frequency Dial. 4 Oscillator Frequency Indicator. 5 Oscillator Range Switch. 6 Q Tuning Condenser Dial. 7 Coil Terminals. 8 Condenser Terminals 9 Q Voltmeter 10 Vernier Tuning Condenser Dial. 11 Vernier Tuning Condenser 12 Q Tuning Condenser. 13 Q Voltmeter Tube. 14 Thermocouple Unit. 15 Oscillator Range Switch Assembly. 16 Oscillator Tuning Condenser. 17 Oscillator Tube. 18 Thermocouple Calibrating Resistor. 19 Oscillator Output Cable. 20 VTVM Zero Adjust. 21 Rectifier Tube. 22 ON-OFF Switch. 23 Pilot Light. 24 HI-LO Switch. 25 Power Unit Nameplate. 26 Thermocouple Filter. 27 Jack. 28 Panel Securing Screws. 29 Oscillator Output Control, Vernier. 30 Dual-Voltage Switch (115-230 volts). 31 VTVM Calibration Control. Photograph f4 SCHEMATIC CIRCUIT DIAGRAM OF TYPE 160-A Q-METER O S C I L L A T O R U N I T P O W E R - V T V M U N I T Fig. 5 CIRCUIT CONSTANTS A N D DESCRIPTION OF PARTS 1 Fixed resistor 1,000 ohms. 27 Power filter choke. 2 Fixed resistor 200 ohms. 28 Power transformer. .-> Fixed resistor 40.000 ohms. 29 "HI-LO"switch. 4 Fixed resistor 2,500 ohms. 30 Line " O N ' - ' O F F " switch. 5 Fixed resistor 750 ohms. x32 • Panel Lamp (Mazda 41, 2.5 volts). 6 Fixed resistor 200 ohms. Oscillator range switch contacts. 7 Potentiometer 8,000 ohms. 33 Oscillator range switch (see note). 8 Potentiometer 200 ohms. 34 Oscillator output voltmeter. 9 Fixed resistor 25,000 ohms. 35 Oscillator output thermocouple. 10 Fixed resistor (1%) 24,000 ohms. 36 R. F. filter for osc. voltmeter. 1 1 Fixed resistor 100 megohms. 37 Q Voltmeter. 12 12a (one unit) Fixed res. • .04 ohms. 38 Oscillator tube (type 102-A). IS Fixed resistor 50,000 ohms. 39 Q voltmeter tube (type 101-A or 101-B). 14 Osc. Tuning Condenser (small). 40 Rectifier tube (type 5W4). 15 Osc. Tuning Condenser (large). 41 Fixed resistor 1,000 ohms. 16. Fixed Condenser .0001 u f . 42 Fixed resistor 0.3 ohms. 17 Fixed Condenser .003 wf. 43 Thermocouple calibrating resistor. 18 Fixed Condenser .005 ttf. 44 Fixed resistor 100 ohms. 19 Q Tuning Condenser (Main). 45 Fixed condenser 0.1 „f. 20 Q Tuning Condenser (Vernier). 46 Shielded Cable. 21 Terminals for test coils. 47 Shielded Cable. 22 Terminals for test condensers. 48 Jack. 23 Power filter condenser, 49 Potentiometer 3,000 ohms. 24 Oscillator grid coil. 50 Potentiometer 1,000 ohms. 25 Oscillator plate coil. 51 Dual-Voltage Switch (115-230 volts). 26 Oscillator coupling coil. a. XOTE: On some oscillator ranges the connections shown in dash lines are made, y t>. XOTE: The jxnver-line j)lug utilizes two Type }AV,—\/*-am\). fuses. 

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