Advertisements

~Oclober, 1952

Vacuum, Vol. I I No 4

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After almost 4 years service In an electron microscope, Dow Cornmg 702 has yellowed slightly but is still as clear and efficmnt as ever

BOW C O R N I N G SILICONE D I F F U S I O N PUMP FLUIDS are second only to mercury in chemical and thermal stability They withstand operating conditions which completely decompose orgamc oils Unaffected by occasional admission of air to a hot system, the tim& are so resistant to oxtdatmn and moismie that they remain clear even after &stxllatton at atmospheric pressure They will not break down to form carbonaceous deposits on ,lets, boilers or fore pumps, have an almost mdefimtely long serwce life Ultimate vacua attainable with Dow Cornmg 703 as well as pumping speeds and hmltmg back pressure are comparable to those obtainable with the best organic oils Dow Cornmg 702 Is used m many ndustnal apphcatmns because ~t has a somewhat lower boiling omt and operates against slightly higher forepressures D O W C O R N I N G H I G H V A C U U M GREASE was especially developed to form a nonmeltmg, nonchannehng, cohesive seal for stopcocks and ground glass lomts under very low pressures and at widely varying temperatures Its low volatflW, combined wtth exceptional stablhty and film strength, makes ~t oss~ble to use th~s s,hcone lubricant m systems vreratlng at pressures as low as 5 x 10 °ram /

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DISTRIBUTOR FOR

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Umted Kingdom - W Edwards & Co (London) Ltd Canada - Fiberglas Lid, Toronto France - St Gobaln, Chauny et Cirey, Paris Also av:~llable thJ:ough distributors of Dow Cornmg products m principal counmes of the world

DOW MIDLAND,

CORNING MICHIGAN,

CORPORATION U.S.A.

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()(~ober, 19~2

PIRANI and IONISATION GAUGE FOR RESEARCH AND INDUSTRY

FEATURES

SPECIAL "A"

Robust

9k"

Slmphfied

"A"

Range

' CATHODEON " COMBINED PIRANI AND IONISATION GAUGE A c o m p a c t , s e l f - c o n t a m e d , m a a n s - o p e r a t e d u m t for m e a s u r m g p r e s s u r e o v e r t h e v e r y w i d e r a n g e o f z m m to zo -6 m m , or less o f m e r c u r y A P l r a m g a u g e is u s e d o v e r t h e r a n g e o f I m m to IO -3 m m B e l o w I o -3 m m a s e l e c t o r s w i t c h b r m g s m a n m n l s a t m n g a u g e i n d i c a t i n g d o w n to I 0 -6 m m or less Occluded gases m t h l s g a u g e m a y b e r e m o v e d b y a b m l t - m " B o m b a r d " feature I n d i c a t o r l a m p s s h o w w h e t h e r t h e i n s t r u m e n t is set to " P~ram, . . . . I o m s a t m n , " or " B o m b a r d " Complete with Plranl a n d I o m s a n o n g a u g e h e a d s w h i c h are n o r m a l l y s u p p h e d m h a r d o r soft g l a s s o f i 2 m m b o r e , b u t are a v a i l a b l e m s p e c m l glasses, b o r e s or c o n n e c t o r s to s u i t c u s t o m e r s ' r e q u l r e m e n t s Descrlpnve lcaflet a ~ a n a b l e o n r e q u e s t .

Probe

Filaments

Controls

extension

readily

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available

W.

G.

PYE

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ENTIFIC~'~qPOINSTRUMENTS

GRANTA

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USE IN

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IN THE FORM OF

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AND

TUNGSTEN CONTACTS FOR ALL APPLICATIONS

TUNGSTEN

MANUFACTURING 68

TELEPHONE VICTORIA 1148

VICTORIA

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TELEGRANS "TUNCONTAC, $OWEST, L O N D O N "

October, 1952

Vacuum, Vol 1I No 4

A COMPLETE LINE of High Vacuum Equipment Oil Diffusion Pumps In a var=ety of sizes from the l-inch laboratory model to the 10-inch high speed production model, these oil diffusion pumps have been g=vmg excellent results when employed on all types of high vacuum equipment Characteristics : High pumping speeds, jets removable for cleaning, multiple jet construction, rigid all-metal exterior

casing.

SC-3 High Vacuum Evaporator This low cost sturdy unit is ideal for shadow casting and other electron m=croscopy work

Also useful m research work,

small scale mwror making and (ow reflection coating. Larger bell lar equipment is avadable

P-6 High Vacuum Evaporator A large industrial unit capable of handling almost any industrial metalhzmg lob in which high vacuum is used Unit illustrated Nscomposed of horizontal cylinders 5 ' m diameter and S' long. One end of welded stainless steel tank swings open, permitting access to complete mterlor As speclahsts m h~gh vacuum equipment, we welcome mquw~es regarding your problems. W r i t e us for hterature glwng detailed specifications on the umts dlustrated

Evaporated Filming Service includmg Low reflection lens coatings, front surface mirrors, beam splitters, dLchrolc mwrors, electrically conducting coatings, etc.

OPTICAL.FILM.ENGINEERING.COMPANY Manufacturers of Diffusion Pumps

• High Vacuum Valves and Baffles • Plastic Metalhzers • Shadow Castmg Un=ts •

Lens Coatmg Units •

Vacuum Metaihzers and

Heat Treating Units, High Vacuum Pumping Systems,

2731-37 N o r t h Sixth Street, Philadelphia

33, P e n n s y l v a n i a , U.S.A.

Vacuum Furnaces.

11 J

l'acuum,

g

October, 1952

Vol I I No. 4

1

The trene strongl

VACUt with

VACUUM PUMPS New products, improved products, reduced costs dady build up the impulse to production processing w]th the a]d of Kinney High Vacuum Pumps

Large scale manufacture of electric lamps and cathode

ray tubes, lens coating, drug production, metal smtermg, typify Innumerable applications whIch 'go one better' on existing products and make profitable propositions of other, quite new ones

GENERAL ENGINEERING CO. (RADCLIFFE) LTD., Station Works, Bury Road, Radcliffe Telephone RADchffe 229z/3 (3 hnes) 1V

Loadon Office 3rd floor, 9 V]ctona Street, London, S W

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Telephone ABBey 5278

October, 1952

Vacuum,

Vol _rI N o

4

Unrivalled for High Vacuum Work in Research and Industry... A PIEZ ON p r o d u c t s c o n t i n u e to represent the latest d e v e l o p m e n t s in high v a c u u m technique.

I n the APIEZON r a n g e

are oils, waxes, greases a n d sealing c o m p o u n d s w h i c h e n a b l e you to p r o d u c e a n d m a i n t a i n pressures from Io -5 d o w n to Io -s m m H g w i t h no d e c o m p o s i t i o n or ' b u m p i n g '

Wr~te to your local Shell Company for a booklet whach describes APIEZON products m detail

u n d e r a wide r a n g e of t e m p e r a t u r e s a n d b a c k i n g pressures

*APIEZON

PRODHCTS

are available throughout the world from local Shell Companies or thetr appointed agents ' ApJuon' ts a Registered Trade Mark of Ap~ezon Products Ltd.

V

I ac*tum,

Vol I I No 4

October, 1952

Centrifuges for preparation and all laboratory routine

~j.~

and research reqmrements... FOR YOUR F I L E : We have just pubhshed a new e&tfon of MSE publncatton858 giving a brief review of the entire range of CentrJfuges Mtcrotomes and Laboratory Blenders Have you had your copy ?

~

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MEASURING & SCIENTIFIC EQUIPMENT LTD., SPENSER STREET, LONDON, S.W.1.

Our speoalmes

include Autoclaves Centrifuges Furnaces

Stills

Ovens Photoelectric

Hotplates Calorimeter

Incubators Water-baths Stirrers Volumetric Glassware Smtered Filtration Apparatus Standard Joint Glassware

A. G A L L E N K A M P & CO. LTD., V1

17-29 S U N

STREET, L O N D O N ,

E.C.2

October, 1952

Vacuum, Vol. I I NO. 4

~UICKFIT)

IN STOCK

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ones

md )ckets :s B7, B10, B12, B I4, B16, B19,~B24, B29, B34, Id B55 are available from stock.

Q I n addition

vays hold substantial stocks of our well-known ehenswe range of interchangeable apparatus. stant~al reductions in price are allowed for ty purchases. QSee that you buy genuine "Quickfit" glassware bearing the trade mark which denotes quality and reliability.Q

QUICKFIT

& QUARTZ

LTD

INTERCHANGEABLE LABORATORY GLASSWARE INDUSTRIAL PLANT IN GLASS

Orders and Enqumes to Dept. 9.C. ,, Q u i c k f l t " W o r k s , H e a r t of STONE, Staffs. Head Office

Phone: Stone 481

1, Albemarle Street, London, W.1

Vll

Vacuum, Vol 11 ~\o 4

INDEX

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TO ADVERTISERS

"ATOMES"

V o l u m e xx - - x954

Great Britain R e s e a r c h Ltd. January, 1, C h a p m a n & Hall Ltd. January, Third Cover, W. E d w a r d s & Co. ( L o n d o n ) L t d . January, iv, April, viii; July, vm, October, ix, A. G a l l e n k a m p & Co. L t d . January, ix, April, v, July, v, October, vl, G a s c o i g n e s , Ltd. January, Vli, April, x, G e n e r a l E n g i n e e r i n g Co. ( R a d c l i f f e ) Ltd. January, viii, April, w , July, Vl, October, iv, L a e y - H u l b e r t & Co. Ltd. January, w b April, m , British American

Measuring&

Scientific Equipment

Ltd.

April, m , July, ii, October, vi, M e t r o p o l i t a n - V i c k e r s E l e c t r i c a l Co. Ltd. January, 1, Murex, Ltd. January, 121, The Physical Society January, Third Cover, April, x, lull, ix, October, vii1, W. G. P y e & Co. L t d . January, ix, April, ix, July, v, October, u, Qulckfit& Quartz Ltd. April, Third Cover, July, m, October, vn, Shell C h e m i c a l s January, 11, April, l, July, 1, October, v, T u n g s t e n M a n u f a c t u r i n g Co. Ltd. January, m , April, v; July, ix, October, n, D a n i e l V a r n e y Ltd. April, vii, July, x,

United States Distillation Products Industries January, x, Dow Corning Corporation January, v, April, Vl, July, iv, October, l, National

Research

This French review of general science contains articles by the best French and lnternatlonal writers, enabhng readers to keep constantly up to date wlth the latest trends Jn scientific and techmcal developments Annual subscription (12 issues) £1 8s 0d

Specimen copy on request (aceompamed by international postal coupon)

" ATOMES

4, Place de l'Od6on, Paris, 66me.

REPORTS ON P R O G R E S S IN P H Y S I C S

Corporation

April, u, July, vii, October, x, O p t i c a l F i l m E n g i n e e r i n g Co. October, U l , Scientific Specialties

Corporation

July, v, Western

Gold & Platinum Works

April, ix;

France ' Atomes

'

October,

VIII,

Italy ' Sclentia '

lanuary, Third Cover; April, x,

Advertising Rates Full page (single inserUon)--(9

~ 6~ i n )

£30 os. od. (U.S. $84) Half page (single msertton)---(9 6¼ in.) j~I5 os. od. (U.S $4~)

V o l u m e XVI (I953) Neutron D~ffraetwn, by G. E. B a c o n and K. L o n s d a l e . Physmal Propertzes and Atomzc Arrangements m Crystals, by W. A. W o o s t e r . Raman Effect m Sohds, by A. C. M e n z i e s . Paramagnenc Resonance, by B. B l e a n e y and K. W. H. S t e v e n s . Semiconductor Czrcuzt Elements, by J. S. B l a k e m o r e , A. E. De B a r r and J. B. G u n n . Elecmcal Dzscharges, by F. L l e w e l l y n Jones. Fluctuatzon Theory m Physzeal Measurements, by C. W. M c C o m h l e . Cosmology, by W. H. M e C r e a . The New Unstable Custom-Ray Partmles, by G. D. R o c h e s t e r and C. C. B u t l e r . Price £2 lOS, postage and packing is 6d

For the use of Publrshmg concernsonly-Quarter page (single lnscrtion)---(4~ 3~ in.)

~7 xos. od. (U.S. $ 2 0 Series discount for four consecutive insertions xo%

Screen for blocks I2o

All advertlsmg matter should refer to products or equipment related to v a c u u m re search and engineering.

All commumcattonsshould be addressedas shownon second cover

rift

"

Orders, wtth remzttances, should be sent to the pubhshers THE I Lowther

PHYSICAL Gardens,

SOCIETY

Prince

L o n d o n , S.W.7

Consort

Road,

Oatober, 1952

Vacuum, Vol I I N o 4

Move to Crawle The new Edwards' factory at Crawley eovers over 100,000 square feet of space devoted to the manufacture of high vacuum eqmpment and to vacuum research Now, more than ever, It will be " Edwards for better vacuum service '" ~o LONO0~

Crawley Is within qmck and easy reach of London, and we look forward to renewing there the friendly personal relationship with vacuum scientists that has long been / such a pleasant feature of our hfe at Lower Sydenham

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~ATK~H TO HO R5HAI'3 ~. pOPTSMOU'FH

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Vacuum,

Vol. I I No *

October, 1952

NOW

You can afford High acuum Furnace Versatile Unit lets you melt, pour,

A t last there is now avmlable a single furnace that does away with the need to purchase equipment for each phase of your tugh-vacuum, high-temperature work. Because of its modest przce, xt wRl fall within the budget of most laboratories. With this new furnace you can melt and sohdify--melt and p o u r - add to the m e l t - - s t i r - - l o o k into the hot zone--measure hot zone temperatures - - introduce controlled atmospheres - - degas - - heat treat. It's a complete, versatile unit, capable of handling the widest variety of metallurgical research work. Write today.

FEATURES Q U l t u n a t e v a c u u m o f less t h a n 5 × IO-~ m m H g . • Working temperatures up to 2ooo ° C.

•

• Temperature controllable wltlun :k5 ° C • Hot zone reaches temperature within two rmnutes. • No refractories used in hot zone. • 4" purifymg type diffusion pump insures high capacity for out-gassing,

larger size are available. • Integral power supply for furnace • Manual temperature control. (Automarac control opuonal). • Thermocouple vacuum gauge is standard eqmpment. Other gauges are available.

HiGH VACUUMENGINEERINGAND EQUIPMENT "

'

•

~

Utthzes smgle turn low voltage resxstance element of tungsten 2½" d l a × 3" h i g h Optxonal heating elements of

METALLURGY DEHYDRATION DISTILLATION COATING APPLIEDPHYSICS

National ResearchCorporation EQUIPMENT

DIVISION

Seventy Memorial Drive, Cambrzdge, Massachusetts

['rmted in Great Brt'ta]n ~by :E T Iloron & Co Ltd

for W Ed',~ards & Co (London)

Istd, Manor Royal

('ra~ley

~u,sox England