Industrial and Engineering Chemistry : analytical edition, Vol. 6, No. 6

A n a l y t i c a l E d i t i o n

V o l . 6 , N o . 6

N o v e m b e r

15, 1934

I n d u s t r i a l

A N D E N G I N E E R I N G

C h e m i s t r y

VOL. 26, CONSECUTIVE NO. 38

Pu b l ic a t io n Of f ic b: Easton, Pa.

Ed it o r ia l Of f ic e:

Room 706, Mills Building, Washington, D . C.

Te l e p h o n e: National 0S48 Ca b l e: Jiechem (Washington)

Ad v e r t is in g De p a r t m e n t: 332 W est 42nd St.,

New York, N . Y . Te l e p h o n e: Bryant 9-4430

Pu b l i s h e d b y t h e Am e r i c a n Ch e m i c a l So c i e t y Ha r r i s o n E . Ho w e, Ed i t o r

C O N T E N T S

15,400 Copies of This Issue Printed A Method for Evaluating the Viscosity-Tempcrature Char­

acteristics of Oils . . IV. It. McClner and M. P. Fenske 389 A Practical Method for Determining Hiding Power of Paints

... A. E. Jacobsen and C. E. Reynolds 393 Specific Refractive Dispersion as a Method for Distinguish­

ing between Different Series of H ydrocarbons...

... A. L. Ward and W. II. Fulweiler 396 Nature and Constitution of Shellac. I X ...

... IVm. Howlell Gardner and Ilarry./. Harris 100 Determination of Sulfide Sulfur in Alkaline Solutions Con­

taining Other Sulfur Compounds . E. L. Baldeschwieler 402 Analysis o f Gaseous Hydrocarbons:

A Method for Determining Ethylene, Propene, and Butcnc ...Hans Tropsch and W. J. Mattox 101 Determination o f the Gasoline Content of Gases . . . .

... Hans Tropsch and W .J . Mattox 405 Determination of Tic Lines in Ternary S y stem s...

... Theodore IV. Evans 408 Chemical Studies of Wood Preservation:

III. Analysis of Preserved T im b e r ...

. . .Robert E. Waterman, F. C. Koch, and IV. McMahon 409 IV. Small Sapling Method of Evaluating Wood Pre­

servatives . Robert E. Waterman and R. R. Williams 413 Indiana Oxidation Test for Motor O ils ...

... T. II. Rogers and R. II. Shoemaker 419 Flame Determination o f Copper by Carbon Tetrachloride .

...Peter Gabriel 420 An Evaporation Hate Method Applied to Petroleum Tliin-

ners...D. D. Rubek and G. IV. Dahl 421 Acidity Titration of Low-Grade Rosins . . Alfred Tingle 422 Micromethods for Determination of Zinc . P. L. Hibbard 423 Quantitative Determination of Ixunl as Periodate . . . .

... Hobart II. Willard and J. J. Thompson 425 Electrometric Determination o f Chlorides in the Ash and

Sap of Plants and in Ground Waters . . . J. R. Neller 426 Determination o f Tellurium in Tellurium Lead and Tel­

lurium Antimonial L e a d ...IV. J. Rrown 428 Metallic Silver as an Ultimate Standard in Volumetric

A n a ly sis... C. IV. Foulk arui L. A. Pappenhagen 430 Estimation o f Aldehydes by the Bisulfite Method . . .

... A. Eric Parkinson and E. C. Wagner 433 Reducing Action of Mercurous Chloride...

... Gordon G. Pierson 437 Determination of the Common and Rare Alkalies in Mineral

A n a ly sis... Roger C. Wells and Rollin E. Stevens 439 Determination of Antimony in Solder . Clifford L. Barber 443 Detection of Calcium in the Presence of Strontium and

B a riu m ...Earle R. Caley 445 Pure Titanium Oxide as a Standard in the Volumetric Esti­

mation o f Titanium . IV. IV. Plechner and J. M. Jarmus 4 47 Inclusion o f Rarer Metals in Elementary Qualitative Analy­

sis. I I ... Lyman E. Porter 448

PotenliometricTitration in NoimqueousSolutions. II . ...Iceland A. Woolen and A. E. Ruehle Determination of Carotene as a Means of Estimating the

Vitamin A Value of F o r a g e ...II. R. Guilbert Determination of Carbonyl Compounds by Means of 2,4-

D initrophenylhydrazine...

Harold /l. Iddles and Carroll E. Jackson Determination o f Small Quantities of Antimony in White Metals... C. IV. Anderson lodomelric Determination o f Phosgene...

...Maryan P. Maluszak A Volumetric Method for Determination of Cobalt and N ic k e l...J. T. Dobbins and J. P. Sanders Volatilization of Iodine from Dilute Iodine-Potassium Io­

dide Solutions...IV. A. Hough and J. II. Ficklen Determination of Naphthalene in Poultry Lice Powders . .

D. S. Binnington and IV. F. Geddes Simple Apparatus for Photoelectric Titration...

... IV. Walker Russell and Donald S. ¡Mlham Oxidation-Reduction Indicators for Use with Dichromate . ...Ixeora E. Straka with Ralph E. Oespcr Apparatus for Roiling Point and Boiling Rungc Measure­

ments . . . D. Quiggle, C. 0. Tongberg, and M. R. Fenskc Apparatus for Melting Point and MicrolKiiling Point . . .

... William L. Walsh A Converted Air-Puinp S lia k e r...Avery A. Morion Apparatas for Measuring Adhesion of Dried Films . . .

...R. P. Courtney anti II. F. Wakefield Stability of Aqueous Solutions o f Boric Acid Used in the

Kjeldahl Method. . . . Abner Eisner and E. C. Wagner Determination o f Artificial Color in W h is k y ...

G .E . Mallory and Peter Valaer Melting Point Apparatus with Rapid Mechanical Stirring . ...K . S. Markley Volumetric Determination of Tungsten . M. l^slie Holt A Simple laboratory Apparatus for Vacuum Distillation .

...Albert IV. Sloul and II. A. Schuetle Ceric Sulfate for Estimating Tin In Rearing Metals . . .

...L.G . Bassett and L . F. Slumpf Cyclohexanol in Colorimetric Determination o f M olyb­

denum Loren C. Hurd and Fred Reynolds Precipitation o f Barium in the Copper-Tin Group o f Quali­

tative Analysis . William T. Hall and Robert B. Woodward Sintered Pyrcx Glass Aeration T u b c s ...

...R. D. Cool and J. D. Graham Gas-Ahsorption Bulb for Use with Small Amounts o f Re­

agent J. A. Shaw

A Salt Bridge for Use in Elcclroinetric Measurements . . George IV. Irving, Jr., and N. R. Smith Author I n d e x ... . . . Subject In dex... ...

449 452

454 456 457 459 460 461 463 465 466 468 469 470 473 474 475 476 476 477 477 478 479 479 480 481 484

Subscription to nonmeinbers, In d u s t r i a la n d En g i n e e r i n g Ch e m is t r y. $ 7 .5 0 per year. Foreign postage $ 2 .1 0 , except to countries accepting mail at American domestic rates. To Canada, 7 0 cents. An a l y t i c a l Ed it io nonly, $ 2 .0 0 per year, single copies 7 5 cents, to members 6 0 cents. Foreign postage, 3 0 cents; Canada, 10 cents. Ne w s Ed it io nonly, $ 1 .5 0 per year. Foreign postage, 6 0 cents; Canada, 2 0 cents. Subscriptions, changes of address, and

■ ' - - ...red to Charles L. Parsons, Secretary, Mills Building, Washington, D . C . _{.1 • • < I t '} . ‘ . . . . I C f\ 4 - . i t l - ,1 ,, I A . f t t o t i n n n d n n itlc ii m m xs.'l 11 h o o I I n n ' a d f o r The Council has voted that no claims will1 Q Q tloc

__________, r Ne w s

claims for lost copies should be referred w v>i»»ueo xj. iw a o u s, ^ 1 0. » . / , , ---; * : ? " V a —' r ; j i • . „ t j , • be allowed for copies of journals lost in the mails, unless such claims are received within 60 days of the date of issue, and no claims will be allowed for issues lost as a result of insufficient notice of change of address. (Ten days’ advance notice required.) Missing from files cannot be accepted as the reason for honoring a claim. If change of address implies a change of position, please indicate its nature.

The Am e r i c a n Ch e m i c a l So c i e t y also publishes the Journal of the American Chemical Society a n d Chemical AbstracU.

4 A N A L Y T I C A L E D I T I O N Vol. 6, No. 6

7 A D V A N T A G E S I N THE N E W C O N T A I N E R S OF M E R C K L A B O R A T O R Y C H E M I C A L S

M e rck L aboratory C h em ica ls are n o w p a ck a g e d in sp e cia lly -d esig n ed con ta in ers w h ich o ffe r these seven im p o rta n t a dvan tages:

1. Amber C olor Glass 2. Non-metallic screw cap 3. W ill not corrode 4. Easy to open

5. Special liner ensures air-tight sealing 6. D ust-proof

7. Attractive appearance T h e am ber c o l o r glass b o ttle s afford m a x im u m p r o ­ te ctio n against lig h t and o th e r d eteriora tin g agents.

T h e n o n -m e ta llic screw caps w ere d e sig n e d to o v e r ­ c o m e c o r r o s io n resu ltin g fr o m u n fa v ora b le a tm os­

p h e ric c o n d itio n s an d fro m v a p o rs p resen t in the la b ora tory . T h e large facets o n th e sid e o f the cap m ak e it easy to o p e n the b o ttle .

A special liner, im p e rv io u s t o the ch e m ica l, e n ­ sures air-tig h t sealin g w h en th e handy ca p is rep la ced . T h e cap ex ten d s o v e r th e lip o f the b o ttle , thus p r e v e n tin g an a ccu m u la tio n o f dust.

M e rck L aboratory C h em ica ls in these n e w a m b er glass b o ttle s, w ith their black caps and b lu e and w h ite labels, w ill add to the attractive appearance o f y o u r la b ora tory o r stock r o o m .

Y o u r w h o le sa le r is ready to su p p ly you .

M E R C K & C O . I nc.

R A H W A Y , N. J

Published by the American Chemical Society, Publication Office, 20tb & Northampton St*., Easton, Pa.

Entered a* second-class matter at the Post Office at Edition, Pa., under »he act of March 3, 187V, as 42 time* a year Industrial Edition monthly on the 1st; New* Edition on the 10th and 20th; Analytical Koition bimonthly on the idth Acceptance for mailing at special

rate of postage provided for in Section 1103, Act of October 3, 1V17, author!*««! July 13, 1918,

" 1

November 15, 1934 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 5

T r a d itio n with F ^{i l t e r}

P ^{a p e r} ?

. ♦ . N o t h i n g

!

s

Adamson will supply you with O N E S IN G L E ALL-PURPOSE FILTER PAPER1

It has every quality you can ask for— and think how it will simplify your work.

1-High Efficiency:

As close to 100% retention, even with fine Barium Sulphate precip­

itates, as is required in ninety-nine percent o f quantitative analysis.

2 -Sp e e d y Filtration:

Faster than anything you’ve ever experienced on fine precipitates—

altogether satisfactory in routine work, or with troublesome pre­

cipitates like Iron or A lum inum .

3 -Strength:

In ample measure for all practi­

cal requirements, particularly when the paper’s speed is

considered.

M M

D o n ’t take our word for it. Prove it, for yourself.

C f i p t h e C o u p o n . .A N D TEST B & A FILTER PAPER ...FR EE!

I

I HERE 'Name...

Address

IF Y O U HAVE N O T RECEIVED A CO PY OF THE NEW B &. A C A T A L O G PLACE A CHECK M A R K G eneral C hem ical C o m p a n y B a k er & A d a m so n D ivision

40 R E C T O R STREET, N E W Y O R K Send me your FREE S A M P L E E N V E L O P E o f B & A Filter Paper Circles, which I will test for a personal observation o f its speed and efficiency.

6 A N A L Y T I C A L E D I T I O N Vol. 6, No. 6

November 15, 1934 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 7

K

< 7a a x>

•I*

20'C'

ntl

KIM

A A

Y hands are needed to perform Ihe delicate and accurate operations required to produce Kimble Exax Blue Line Graduated Glassware. Nothing short of perfection is good enough. Men skilled and trained through years of glassmaking experience are em­

ployed continuously performing the complicated steps necessary tc pin the various sections of a piece of scientific glassware into a complete unit.The finished article must befree of flaws and blemishes.

The result of Kimble’s painstaking attention to detail and work­

manship is that when burette or pipette or any other piece of Exax Blue Line Glassware reaches the laboratory there is no doubt about its quality, strength and accuracy. Standardize on Kimble’s—for assurance!

G r i n d i n g the stopcocks o f Kim bl e Burettes is a n im p o r t a n t h a n d o p e r a ­ tion p e r fo r m e d b y the highest ty p e o f skilled artisan. A l l K im b l e stopcocks a r e a c c ur a te ly g r o u n d a n d tested a g a in s t a v a c u u m o f 1 5 " o f mer cu ry .

3LE GLASS C O M P A N Y

V I N E L A N D , N E W J E R S E Y .

N E W Y O R K • P H I L A D E L P H I A • B O S T O N

C H I C A G O • D E T R O I T

8 A N A L Y T I C A L E D I T I O N Vol. 6, No. 6

COORS

CHEMICAL A N D SCIENTIFIC

PORCELAIN

C oors P orcelain C o .

GOLDEN, COLORADO

CURRENT PRACTICE IN COM BUSTION M ETH O D S

The C H E V R O L E T M O TO RS Com bustion T ra in

STAINLESS STEEL

M O N E L M E T A L

are used to advantage in many instances w h e re their chemical resisting p ro p e r­

ties are called for. The stainless steel and monel metal basket type heads are furnished w ith draining chambers of The same ma­

terial.

BASKET TYPE HEADS

for the International Size 1 and Size 2 Centrifuges, either solid or perforated, are n o w available In tw o sizes ( 8 ' and 1 1 ' diameter) made o f :

Stainless Steel Monel Metal Manganese Bronze

INTERNATIONAL EQUIPMENT CO.

352 Western Avenue Boston, Mass., U. S. A .

M a k e r* o f F i n e C e n t r i f u g e •

The more recent trends in combustion equipment have been directed toward simplification of purifying, absorbing and protecting units, higher temperatures, automatic control of temperature and larger combustion tubes.

Records of routinely operated equipment indicate that by the use o f combustion tubes as large as 2 inches outside diameter, complete combustion of sample is accelerated and the life of the combustion tube may be multiplied as much as 10 times.

Such changes as have been made from time to time in purifying and absorbing units have a principal object of pro­

moting ease of assembly, handling, and replacement. We believe the Chevrolet Motors train offered here is in every sense a highly efficient and practical outfit for modern metallurgical laboratories.

W R I T E F O R O U R D E S C R I P T I V E B U L L E T I N 155-165 E. S U P E R I O R S T . , C H I C A G O

S U P P L IE S

November 15, 1934 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 9

G A S W A S H IN G BOTTLE made after G REIN ER & FRIEDRICHS

2000 2002

Constructed of Corning Resistant and Lime Glass made in this Country— our own manufacture

T h e action o f this bottle is such that the gas bubbles rise through the spiral section assuring you o f satisfactory ab - [ sorption. T h e liquid is prevented from rising to the top by the center reflux tube, insuring continuous circulation.

40 m m . diameter 100 m l. capacity

Experience has shown this to be one o f the m ost efficient gas washing bottles on the m arket.

N o . 2000 C orn in g R esista n t G lass w ith g rou n d -in sto p p e r $7 .5 0 ea.

N o . 2001 C orn in g R esista n t G lass w ith ru b ber sto p p e r 5.0 0 ea.

N o . 2002 L im e glass w ith grou n d -in sto p p er 4 .7 5 ea.

N o . 2003 L im e glass w ith ru b ber sto p p e r 3 .2 5 ea.

N o te : B ottle with ground-in stop p er can be su p p lied w ithout rubber stop p er attachment to tube, at top.

S C I E N T I F I C G L A S S A P P A R A T U S C O .

4 9 Ackerman Street Bloomfield, N . J. ²⁰⁰¹2003

■ 1 1 1 Ü 1 H i

t

HIGH TEMPERATURE

Combustion Tube Furnace

T h is H igh Tem perature E lectric T u b e Furnace is designed, chiefly, for the determ ination o f carbon in ferrous alloys, b y the d irect-com bu stion -in - oxygen m ethod, where tem peratures from 2 00 0 to 2 30 0 deg. F . are required.

T h e furnace m a y be used, also, for standard com bustions; special organic analysis; pyrom eter checking and calibrations; and heat treating or ex­

perim ental operations which require temperatures from 1100 to 2 3 0 0 deg. F .

T em peratu re regulation is accomplished by m eans o f a regulating transform er— thus elim inating the necessity o f a rheostat and thereby saving a current loss if the rheostat were used. T h e Furnace costs $ 75 .0 0 . A transformer, 110 or 2 20 volts (voltage m u st be specified) for 60 cycles costs $ 5 0 .0 0 ;

°r 25 - 1 s ?57 6°

W m r r O R P O R A T IO N

d e scrip tion w ill be fu r­

n ish ed o n requ est.

L A B O R A T O R Y A P P A R A T U S A N D C H E M I C A L S

C H E M I C A L . B I O L O G I C A L . M E T A L L U R G I C A L A N D C L I N I C A L L A B O R A T O R I E S

B

, X Y '

10 A N A L Y T I C A L E D I T I O N Vol. 6, No. 6

A. H. T. CO . S P E C IF IC A T IO N

R E S E R V O I R B U R E T T E S

A N E W SERIES, O F I M P R O V E D C O N S T R U C T I O N

Fig. A

Showing details of con­

struction of automatic zero control device

Fig. B

Showing method thumb control of vent in rubber bulb

of air

RESERVOIR BURETTES, A.H.T. Co. Specification. A new series, developed from the Knoefler and Squibb so- called “ Automatic” Burettes but of improved and more rugged construction, embodying all practical features of the earlier models and obviating the use of special clamps. The delivery stopcocks are sufficiently extended beyond the reservoir to permit convenient use with beakers or Erlenmeyer flasks up to 1000 ml capacity.

The burettes are all of the Schellbach type, of 50 ml capacity, with graduation interval of 0.1 ml and volume adjustment of =*=0.10 ml, which is equal to percentage of error of 0.2%. The reservoir bottles arc of 2000 ml capacity, of hard resistance glass of minimum solubility. The pressure bulbs are provided with an air vent in the connecting tube for convenient thumb control.

2473. Burette, Reservoir, A .H .T . Co. Specification, as above described, with open top, i.e. without automatic zero device, but with stopcock permitting return of unused solution to reservoir. W ith rubber stopper connection... 9.00 2474. Ditto, but with ground glass join t... 11.00 2476. Burette, Reservoir, A .H .T . Co. Specification, with automatic zero device at top of burette and with side tube for filling and overflow. Bore of burette permanently closed between delivery tube and reservoir. W ith rubber stopper connec­

tion... 10.00

2477. Ditto, but with ground glass join t... 12.00

2482. Burette, Reservoir, A .H .T . Co. Specification, identical with N o. 2476, i.e. with automatic zero device, but with stopcock below the inclined delivery tube for return of unused solution to reservoir. W ith rubber stopper connection... 12.00 2483. Ditto, but with ground glass join t... 14.00

P rices s u b je c t to c h a n g e w i th o u t n o tic e .

Code Word

Bietr Bievn

Bifad Bifev Bigho Bigki

CLEAR AN CE SALE PR ICE S O N R E M A IN IN G S T O C K OF O LD M O D E L S

W e offer, subject to prior sale, our remaining stocks of the old model Burettes as illustrated on page 122 of our catalogue at the follow­

ing special prices:

38 2480 Burettes, Squibb’ s Improved Zero, 25 ml in ‘/¡» th s ...Each 5.00 12 “ Ditto. 5 0 ml in Vioths... “ 5.00 40 2484 Burettes, Squibb’ s Automatic Zero, Original Form, 50 ml in l/ioths... Each 4.00

A R TH U R H. T H O M A S C O M P A N Y

R E T A I L — W H O L E S A L E — E X P O R T

LA BO RA TO R Y APPA RA TU S AND REA G EN TS

W E S T W A S H IN G T O N S Q U A R E P H IL A D E L P H IA , U.S.A.

Cable Address, “ BALANCE,” Philadelphia

A N A L Y T I C A L E D I T I O N

I n d u s t r i a l

V o l u m e

6 A N D E N G I N E E R I N G

15,

nu„beb 6 C h e m i s t r y 1934

Pu b l i s h e d b y t h e Am e r i c a n Ch e m i c a l So c i e t y Ha r r i s o n E . Ho w e, Ed i t o r

A Method for Evaluating the Viscosity - Temperature Characteristics of Oils

W . B . M^cC^{l u e r a n d} M . R . F^{e n s k e}

P etroleu m R efin in g L a b o ra to r y , P e n n sylva n ia S ta te C o lleg e, S ta te C olleg e , P a.

W

teristics of oils m ay be varied appreciably, the prob­

lem of evaluating the viscosity characteristics of different lubricants over a wide range in temperature becomes increas­

ingly important. This is especially true of automotive lubri­

cants, because the mechanical parts must be lubricated satis­

factorily both at relatively low temperatures and at the rela­

tively high temperatures encountered in severe operating conditions.

A satisfactory motor lubricant must serve at least two pur­

poses: ( 1) the lubricant must be sufficiently fluid at low temperatures so that the car can be started readily and the various parts m ay receive oil during starting; (2) the lubri­

cant must be sufficiently viscous at higher temperatures so that the parts o f the motor m ay not suffer undue wear during long periods of operation at engine temperatures. For these reasons, it is generally recognized that a lubricant whose vis­

cosity changes slowly with temperature is more satisfactory under severe operating conditions than another lubricant whose viscosity changes rapidly with temperature.

The fact that an oil must be relatively viscous at higher temperatures is readily apparent since many of the parts to be lubricated operate at elevated temperatures. It may not be so obvious that an oil must be relatively fluid at low tempera­

tures. Larson (3), Becker (I), and Blackwood and Rickies (S) have shown that the power required to start a car in cold weather is directly related to the viscosity of the crankcase lubricant at the starting temperatures. Lederer and Zublin (11) have shown that the pumpability of an oil at low tem­

peratures is dependent in a large measure on the viscosity of the oil at operating temperatures and to a lesser degree on the pour point of the oil. For these reasons, it is desirable that the rate of change of viscosity with temperature for the crankcase lubricant be as low as possible.

Various means for evaluating and comparing oils with re­

spect to their relative rates of change o f viscosity with tem- jierature are available. These m ay be listed as follows:

1. Ratio of the 100° F. (37.8° C.) viscosity to the 210° F.

(98.9° C.) viscosity.

2. Viscosity index as developed by Dean and Davis (7) and Later revised by Davis, Lapeyrouse, and Dean (6).

3. Viscosity slope number developed by Bell and Sharp (2)

by means of arbitrary arithmetical scales superimposed on the A. S. T. M. viscosity-temperature chart, D-341-32-T.

4. Viscosity gradient devised by Clayden (/,) for expressing the viscosity temperature slope of oils by means of angles and fundamental viscosity units.

5. Viscosity-gravity constant introduced by Hill and Coates (8) in 1928 as a means for evaluating the paraffinicity or naph- t henicity of oils.

6. Viscosity gravity zones recommended by Larson and Schwaderer (10) in 1932 and 1933 as a means for graphical esti­

mation of relative viscosity-temperature characteristics.

7. Gravity index (12) based on an empirical relation between viscosity-gravity constant and viscosity index.

Each of these several methods for comparing lubricating oils with respect to their viscosity-temperature characteristics may be divided roughly into two classes, depending upon whether they are based directly upon viscosity-temperature charts or upon a comparison with certain specific types of oil. Each method of classifying oils appears to have certain fairly well defined advantages and disadvantages, but there is no apparent means by which the advantages of each classi­

fication may be retained. None of the methods result in a quantitative expression of the actual viscosity at low or high temperatures. Therefore, for the purpose of obtaining fur­

ther means of comparing oils in this respect it has appeared desirable to start with an entirely different reference basis.

The purpose of this paper is to outline a method by means of which the viscosities o f different oils m ay be compared quan­

titatively, either at the low temperatures encountered in

«•inter starting or at the high temperatures encountered dur­

ing motor operation.

With the present lack of information on the materials which compose petroleum, it appears practically impossible to develop a method for evaluating this characteristic of lu­

bricating oils on an absolute basis. For this reason, practi­

cally any method devised at the present time for this purpose must be established on a relative and comparative basis.

From the point of view o f comparing the performance of lubri­

cants in service in so far as this is dependent upon viscosity, it seems logical to evaluate oils at tw o temperature extremes, one high and one low. Also, practical engineering usefulness dictates that fundamental units such as the stoke or poise be used instead o f arbitrary units o f viscosity such as Saybolt seconds.

389

390 A N A L Y T I C A L E D I T I O N Vol. 6. No. 6

Ta b l e I . Vi s c o s i t y- Te m f e r a t u u e Re l a t i o n s o f Oil s

Zer o Vis c o s it y

Fa c t o r 0 . 1 0 . 2 0 . 4

0.60 .8 2 .01.0

4 . 0 6 . 0 8 .0 10.0 2 0.0 4 0 . 0 6 0 . 0 8 0 . 0 100.0 0.1 0.2 0 . 4 0 . 6 0 . 8 1 .0 2 . 0 4 . 0 6 . 0 8 . 0 10.0 20.0 4 0 . 0 6 0 . 0 8 0 . 0

100.0

0.1 0.2 0 . 4 0 . 6 0 . 8 1 . 0 2 . 0 4 . 0 6 . 0 8 . 0

10.020.0 40.0 6 0 . 0 8 0 . 0 100.0

Ki n e m a t i c Vi s c o s it y ( Ce n t i s t o k e s) 210° 40 0 6 F .c F.d 100° F.6 (9 8 .9 °(2 0 4 .4 °

Ki n e m a t ic Vis c o s i t t ( Ce n t i s t o k b s) Ki n e m a t ic 1

0 ° F .°

- 1 7 . 8 ° C.•)

143.1 2 8 6 .2 5 7 2 .4 8 5 8 .6 1,145 1,431 2,862 5,724 8,586 11,450 14,310 28,620 57,240 85,860 114,380 143,100 2,080 4,160 8,320 12,481 16,641 20,801 41,602 83,20-1 124,806 166,408 208,010 416.020 832.040 1.248.060 1,664,0S0 2,080,100 20,701 41,402 82,80-4 124,206 165,608 207,010 414.020 828.040 1.242.060 1,656,080 2,070,100 4,140,200 8,280.400 12,420,600 16,560,800 20,701,000

(37.8° C.) 17.12 2 1 .7 0 2 4 .8 0 2 7 .4 5 2 9 .4 0 3 0 .9 0 3 6 .1 0 4 2 .0 4 4 5 .8 9 4S .44 5 0 .8 7 5 8 .1 3 6 8 .7 1 7 1 .1 8 7 5 .1 9 7 8 .2 0 8 7 .7 8 106.3 127.6 142.2 15 2 .0 160.9 189.4 22 2 .5 2 4 4 .0 2 6 1 .1 2 7 3 .6 3 1 8 .2 3 6 8 .0 4 0 0 .2 4 2 3 .6 4 4 3 .0 3 7 7 .4 4 5 7 .0 5 4 8 .9 6 1 5 .8 6 6 1 .1 7 0 2 .0 8 3 3 .8 9 8 7 .8 1093 1166 1233 1438 1686 1844 1963 2058

C.) C.) 5 .0 5 .0 5 .0 5 .0 5 . 0 5 .0 5 . 0 5 .0 5 .0 5 .0 5 .0 5 . 0 5 .0 5 . 0 5.0 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 1 5 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0 4 0 .0

1 .6 2 1.53 1 .3 2 1.25 1.21 1 .1 9 1. 11

1.011.01

0 .9 9 0 .9 7 0 .9 2 0 .8 9 0 .8 6 0 .8 5 0 .8 4 3 .2 7 2.96 2 .7 1 2 .5 9 2 .5 1 2 .4 5 2 .3 1 2 .1 5 2 .0 7 2 .0 3 1.99 1 .8 9 1 .8 0 1 .7 5 1 .7 2 1 .7 0 6 .0 8 5 .1 1 5 .0 7 4 .8 3 4 .6 7 4 .5 6 4 .2 5 3 .9 7 3 .8 4 3 .7 4 3 .6 7 3 .4 7 3 .2 9 3 .2 0 3 .1 4 3 .0 3

210° 400° 21 0 ° 4 0 0 °

Vi s­ F .c F.d Vi s­ F .c F.d Vi s­

c o s it y 0 ° F .° 100° F. 6(98.9° (204.4°c o s it y 0 ° F .° 100° F.6 (98.9° (204.4°c o s it y In d e x ( - 1 7 . 8 ° C .)(3 7 .8 ° C. ) C.) C.) In d e x ( - 1 7 . 8 ° C .) (3 7 .8 ° C.) C.) C.) In d e x

187 3 2 9 .2 2 8 .2 9 7 . 0 2 .0 1 170 7 8 7 .1 4 8 .1 2 1 0 .0 2 .5 2 155

158 6 5 8 .4 3 4 .2 3 7 . 0 1 .8 0 153 1,574 5 8 .1 4 1 0 .0 2 .2 8 141

139 1,317 4 0 .9 2 7 .0 1 .6 5 133 3,148 6 9 .3 5 1 0 .0 2 .0 9 126

122 1,975 4 5 .3 4 7 .0 1.57 119 4,723 7 7 .3 1 1 0 .0 1.99 115

109 2,634 4 8 .5 0 7 . 0 1.52 110 6,297 8 2 .7 8 1 0 .0 1 .9 3 108

99 3,292 51 .2 1 7 . 0 1.49 101 7,871 8 7 .5 0 1 0 .0 1 .8 8 101

65 6,584 6 0 .0 2 7 . 0 1 .3 9 74 15,742 102.7 1 0 .0 1 .7 5 81

25 13,170 6 9 .9 4 7 . 0 1 .3 0 44 31,484 12 1 .0 1 0 .0 1 .6 5 56

- 1 19,750 7 6 .5 1 7 . 0 1 .2 6 24 47,226 1 3 2 .0 1 0 .0 1 .6 0 41

- 1 8 26,340 8 0 .9 5 7 . 0 1 .2 3 10 62,968 14 1 .1 1 0 .0 1 .5 5 28

- 3 4 32,920 8 6 .1 2 7 . 0 1.21 - 6 78,710 14 8 .2 1 0 .0 1 .5 3 18

- 8 4 65,840 9 9 .5 0 7 . 0 1.15 - 4 7 157,420 16 9 .5 1 0 .0 1 .4 6 - 1 1

- 1 5 5 131,700 11 2 .0 7 .0 1 .1 0 - 8 6 314,840 1 9 5 .8 1 0 .0 1.37 - 4 8

- 1 7 2 197,500 12 0 .6 7 . 0 1 .0 8 - 1 1 3 472,260 2 1 0 .4 1 0 .0 1 .3 5 - 6 8

- 1 9 8 263,400 127.6 7 .0 1 .0 6 - 1 3 5 629,680 2 2 4 .5 1 0 .0 1.33 - 8 7

- 2 1 9 329,200 132.6 7 . 0 1.05 - 1 5 1 787,100 2 3 3 .7 1 0 .0 1 .3 1 - 1 0 0

146 4,109 13 4 .9 2 0 .0 3 .9 3 138 10,590 2 4 6 .1 3 0 .0 5 .0 8 131

135 8,217 163.1 2 0 .0 3 .5 6 128 21,180 2 9 7 .9 3 0 .0 4 .6 1 123

122 16,434 196.1 2 0 .0 3 .2 6 117 42,360 3 5 8 .6 3 0 .0 4 .2 2 114

113 24,652 2 1 8 .5 2 0 .0 3 .1 2 110 63,540 4 0 0 .1 3 0 .0 4 .0 3 108

107 32,869 2 3 4 .1 2 0 .0 3 .0 2 105 84,720 4 2 9 .5 3 0 .0 3 .9 0 10-1

101 41,086 2 4 7 .8 2 0 .0 2 .9 5 100 105,900 4 5 5 .6 3 0 .0 3 .8 5 100

84 82,172 2 9 2 .9 2 0 .0 2 .7 5 85 211,800 54 0 .1 3 0 .0 3 .5 5 88

73 164,340 3 4 4 .8 2 0 .0 2 .5 8 68 423,600 6 3 8 .4 3 0 .0 3 .3 3 74

51 246,520 3 8 0 .3 2 0 .0 2 .4 9 56 635,400 7 0 5 .0 3 0 .0 3 .2 1 64

41 328,690 4 0 4 .3 2 0 .0 2 .4 3 48 847,200 7 5 2 .7 3 0 .0 3 .1 3 57

33 410.S60 4 2 6 .8 2 0 .0 2 .3 9 41 1,059,000 7 9 3 .9 3 0 .0 3 .0 8 51

5 821,720 4 9 5 .9 2 0 .0 2 .2 7 17 2,118,000 9 2 6 .7 3 0 .0 2 .9 1 32

- 2 6 1,643,440 5 7 5 .0 2 0 .0 2 .1 6 - 9 4,236,000 1080 3 0 .0 2 .7 7 9

- 4 5 2,465,160 6 2 6 .1 2 0 .0 2 .0 9 - 2 6 6,354,000 1176 3 0 .0 2 .6 9 - 6

- 5 9 3,286,880 6 6 5 .7 2 0 .0 2 .0 5 - 4 0 8,472,000 1250 3 0 .0 2 .6 4 - 1 7

- 7 1 4,108,600 6 9 7 .4 2 0 .0 2 .0 3 - 5 0 10,590,000 1311 3 0 .0 2 .5 9 - 2 9 127

120 113 107 104 100 90 77 69 63 57 40 196

- 4 - 1 2

a For oils having a zero viscosity factor of 1, the viscosity at 0 ° F . ( —17.8° C .) was calcu­

lated from the 1 0 0 °.F. (37.8° C .) and 2 1 0 ° F . (98.9° C .) viscosities by Equation 2. All other viscosities at 0 ° F. are definite percentage amounts, depending upon the numerical value of the zero viscosity factor of the 0 ° F , viscosity of the reference oil.

t> For oils which have a zero viscosity factor of 1, the 100° F . viscosity was calculated from the 2 1 0 ° F . viscosity by Equation 1. A ll other viscosities at 100° F . were calculated by means of Equation 2, since the viscosities of these various oils were known at temperatures of 2 1 0 ° and 0 ° F.

. * yiscosity at 2 1 0 ° F ., at which temperature all oils which are to be rated in terms of viscosity ratio at 0 ° F . have equal viscosity.

d Viscosity calculated by Equation 2.

Pr o p o s e d M e t h o d

The proposed method for comparing the viscosity-tempera- ture characteristics o f lubricating oils is largely mathemetical in nature and depends on relatively simple procedures and concepts. The steps m ay be outlined as follows:

1. A single type of oil is used for reference purposes.

2. Comparisons are made with oils having equal viscosities at 210° F. (98.9° C.).

3. The 100° F. (37.8° C.) viscosity of the reference oil is expressed in terms of its 210° F. (98.9° C.) viscosity by a simple equation.

4. The viscosity of the reference oil can be calculated at any other temperature by known relations.

5. All oils, if matched as to viscosity at 210° F. (98.9° C.), have a definite viscosity ratio at 0° F. ( — 17.8° C.) with respect to the reference oil.

6. The 100° F. (37.8° C.) viscosity of any oil having known viscosities at 0° F. ( — 17.8° C.) and 210° F. (98.9° C.) can be calculated.

7. The mathematical results can be expressed accurately by means of a simple nomograph.

The 100° F. (37.8° C .) viscosities, Y, of the reference oils were calculated for given viscosities at 210° F . (98.9° C .), X , b y means o f the following equation.

log,, Y = 1.502 log« X + 0.4400 (1) This equation m ay be considered as defining the viscosity characteristics of hypothetical oils for the purpose o f estab­

lishing a reference standard, or it may be considered as de­

fining the viscosity characteristics o f actual oils, since for all practical purposes the equation satisfactorily correlates the viscosity-temperature characteristics of oils refined from an extreme type of paraffin-base crude oil.

When the viscosities of a lubricating oil are known at two

temperatures, the viscosity at a third temperature can be calculated by well-known relations. T w o equations which are probably better known than others are Cragoe’s (5) and the one employed b y the American Society for Testing M a­

terials for developing the viscosity-temperature chart desig­

nated as D-341-32-T. These two equations result in approxi­

mately similar results, but the calculations in this paper are based on the A .S . T . M . equation, which is probably more widely known and used than Cragoe’s equation. The A .S .T .M . equation (IS) is:

log log {K V + 0.8) = A log T + B (2) where K V is kinematic viscosity in centistokes, T is absolute temperature, and A and B are constants. Use of this equa­

tion instead of the A .S .T .M . viscosity-temperature chart is desirable, because the errors inherent in graphical extrapola­

tion and interpolation are eliminated.

The results presented in this paper are based on Equations 1 and 2, plus the concept that oils matched as to viscosity at 210° F. (98.9° C .) have different viscosities at 0 ° F . ( —17.8°

C .) depending upon their viscosity-temperature characteris­

tics, and that the latter m ay be expressed as the ratio of the 0 ° F. ( —17.8° C.) viscosity of any given oil and the 0 ° F.

( — 17.8° C.) viscosity of a reference oil. For conciseness, this viscosity ratio at 0 ° F. ( —17.8° C .) has been termed the

“ zero viscosity factor.” The numerical value o f this factor is a quantitative measure o f the 0 ° F. ( — 17.8° C .) viscosity of an oil, since the product of the 0 ° F. ( —17.8° C.) viscosity of the reference oil and the determined zero viscosity factor is the 0 ° F. ( — 17.8° C.) viscosity o f that oil. All viscosities are expressed in terms of kinematic viscosity (centistokes), in order that fundamental units m ay be used.

November 15, 1934 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 391 B y choosing any given viscosity at 210° F. (98.9° C.) for

the reference oil, and b y assigning a definite value for the viscosity ratio at 0 ° F. ( —17.8° C .), it is possible to calculate the 0 ° F. ( —17.8° C .) and 100° F. (37.8° C.) viscosities of oils having the assumed viscosity characteristics.

Fi g u r e 1 . Gr a p h i c a l Re p r e s e n t a t i o n o p Me t h o d Us e d i n De v e l o p i n g Ze r o Vi s­

c o s i t y Fa c t o r

T he method followed in establishing the zero viscosity fac­

tor mathematically is indicated graphically b y Figure 1.

The viscosity-temperature characteristics of four oils are represented, two oils having 210° F. (98.9° C.) viscosities of 5 centistokes and the remaining two oils having 210° F. (98.9° C.) viscosities of 30 centistokes. The 100° F. (37.8° C.) viscosities of the light and heavy reference oils designated by points B and G, respectively, were obtained from the 210° F. (98.9° C.) viscosities of 5 and 30 centistokes, respectively, by means of Equation 1. The 0° F. ( — 17.8° C.) viscosity of the light and heavy reference oils were obtained from their respective vis­

cosities at 100° F. (37.8° C.) and 210° F. (98.9° C.) by solving Equation 2. The 0° F. ( — 17.8° C.) viscosity of oil 1 was ob­

tained by multiplying the 0° F. ( — 17.8° C.) viscosity of^the light reference oil by a zero viscosity factor of 10 and its 100° F.

(37.8° C.) viscosity was obtained by substituting viscosities at 0° F. (-1 7 .8 ° C.) and 210° F. (98.9° C.) in Equation 2.

Oil 2 is matched as to viscosity at 210° F. (98.9° C.) with a reference oil having a viscosity at 210° F. (98.9° C.) of 30 centi­

stokes. By assuming a zero viscosity factor of 5 for oil 2, it is possible to calculate the viscosities of oil 2 at temperatures of 100° F. (37.8° C.) and 0° F. (- 1 7 .8 ° C.). Having established the 100° F. (37.8° C.) and 210° F. (98.9° C.) viscosities of oils in this manner, it. is possible to calculate the viscosity index of oils having definite zero viscosity factors. Also the viscosity of oils having definite viscosity relations at 0° F. ( — 17.8° C.) may be calculated at any desired temperature (say, 400° F.) by solving Equation 2.

The viscosity-temperature characteristics of a large number of oils having different 210° F. (98.9° C.) viscosities and different zero viscosity factors have been calculated by the method indi­

cated above. Calculated data for oils having viscosities at 210° F. (98.9° C.) from 5.0 centistokes (a light oil) to 40.0 centi­

stokes (an extremely heavy oil) and having zero viscosity factors from 0.1 to 100 are contained in Table I.

The data contained in Table I have been used as a basis for constructing a nomograph (Figure 2) b y means of which the zero viscosity factor of oils may be determined readily from

the viscosity at 210° F. (98.9° C.) and 100° F. (37.8° C .).

The chart is used by connecting the points representing the viscosities of an oil at 210° F. (98.9° C.) and 100° F. (37.8°

C .) with a straight edge and reading off the value of the zero viscosity factor at the point where the straight edge inter­

sects the sloping line on the right-hand side o f the chart.

The three scales shown are logarithmic and interpolations should be made with this in mind.

The data contained in Table I indicate further that the viscosity index o f oils is n ot an absolute criterion o f relative viscosities at low temperatures. For example, oils which are 10 times more viscous than the standard reference oils at 0 ° F. ( —17.8° C .) and have 210° F. (98.9° C .) viscosities o f 5.0, 15, and 30 centistokes require viscosity indexes of —34, + 3 0 , and + 5 1 , respectively. These variations in viscosity index are probably greater than would be anticipated for oils having a constant viscosity ratio at 0 ° F. ( —17.8° C .). It is indicated therefore that viscosity index alone is not suf­

ficient for accurately evaluating the 0 ° F. ( —17.8° C.) vis­

cosity characteristics o f oils. Oils having a zero viscosity factor of 1.0 have viscosity index values o f approximately 100 through a range in viscosity at 210° F. (98.9° C .) of 5.0 to 40 centistokes. T h e relation between viscosity index, 210° F. (98.9° C.) viscosity, and zero viscosity factor o f oils is reversed when oils have zero viscosity factors less than 1.0.

For example, oils having a zero viscosity factor of 0.1 and 210°

F. (98.9° C.) viscosities of 5.0, 15, and 30 centistokes have viscosity indexes of 187, 143, and 131, respectively. Signifi­

cant differences in viscosity index are therefore less impor­

tant in the case of light oils than in the case of relatively heavy oils.

-1-400 350

300

250

200

- 1 5 0

100 80 to

60

2000

1000

too 600

400

300

*>- -200

10

•*-»

F i c u n E 2 . No m o g r a p h f o r Ob t a i n i n g Ze r o Vi s c o s i t y Fa c t o r o f Oi l s

Variations in viscosity index such as those indicated above are not unusual when the viscosity index concept is applied to theoretical considerations. If the ideal lubricant is de­

fined as an oil whose viscosity does n ot change with tempera­

ture, it is possible to calculate the maximum theoretical vis­

cosity index for such oils having different viscosities at 210°

F. (98.9° C .). When these calculations are made, it is found