Vacuum news

around a specific area or volume within the chamber, also includes a 180'" calibrated protractor angle indicator for high-accuracy position- ing of specimens. Other standard fecd-throughs are also a,,ailablc and any standard model may be adapted and modified for special applications. Where required, high vacuum ball seals may be provided for universal movement including translatable motion, push-pull movement, and full 363 rotation. Denton Vacuum lne, USA Circle number 60 on Reader Enquiry Service card

New Triplex series of vibrationless high vacuum pumps Kinney Vacuum Division, the New York Air Brake Co, has incor- porated their patented balancing technique into the development of a new line of high vacuum pumps. The balancing technique affords vibration-free pumping from 150 cfm to 850 cfm. This feature is claimed to be unique. The Triplex series includes 150, 300, 500 and 850 cfm models. The compact design and robust construction of these pumps reduce floor space requirements and minimize down- time. Ultimate pressures below 10 ~ lorr arc reached. Operational details are presented in a catalogue, Bulletin 3125.1. Kinney Vacuum Division, USA Circle number 61 on Reader Enquiry Service card

obtained by application to Sloan Instruments Corp, PO Box 4608, Santa Barbara, California, USA. Also offered is an eight-minute 16 mm colour sound film showing the latest techniques in automatic control of multi-layer multi-source depositions. It is freely available on a one-week loan basis and follows a layered evaporation process through pumpdown, preheat and degassing cycles, automatic rate and thickness control, source switching, sequence recycling and final venting.

High vacuum equipment catalogue Ferranti Limited (Electronics Department) of Gem Mill, Chadderton, Oldham have issued the 1967 edition of their high vacuum equipment catalogue covering Getter ion pumps and control units (0.2, 1, 8, 15, 80, 140 and 500 litres/second), absorption pumps, sublimation pumps, valves, flanges, gaskets and other accessories. Complete systems are also available. Individual data sheets for the equipment described are in preparation and will be available in the near future.

Control instrumentation Ether Limited of Stevenage, I-lerts, have recently issued brochures illustrating their wide range of control instruments for temperature, pressure, vacuum, and power supply. The Company's pressure transducers, applicable under rough to medium vacuum conditions, incorporate a patented, gravity-compensated, frictionless movement. Control valves, electrical motors and connectors and data processing equipment are included in the product range.

Shell temporary protectives for corrosion prevention The complete range of Shell Ensis protectives and the Shell vapour phase inhibitors and their applications are described in a 76 page booklct published by Shell International Petroleum Company Limited. These fluids and compounds find general application in the cleaning, drying and sealing of mechanical equipment and plant. Shell Ensis Oil 158 is recommended for the internal treatment of compressors and mechanical vacuum pumps.

Vibrationless high vacuum pumps

Simulation chamber for corona discharge research The French group Alcatel-Hcurtey have recently constructed a space simulation chamber designed for corona discharge investigations to be carried out at L'Organisation Europ6enne de Recherches Spatialcs (ESRO) in Nordwijk (Netherlands). Constructed in polished stainless steel the chamber has a volume of 10 m :~ and can bc pumped do',~n from 760 to 100 torr in 38 seconds by the primary pump or in 34 seconds with three pumps. This rapid pressure reduction simulates the initial 30 km of satellite flight. Pressures in the range 10 torr to 5 x 10 -~ torr may be reached in 38 minutes by means of two Alcatcl secondary systems each consisting of a 180 m3/hour primary pump, an oil diffusion pump (11,000 litrcs/second), equipped with an optical baffle, and three pneumatic fans. Control may be manual or automatic. At each range of operation pressure adjustments may bc made by two needle-valves.

N e w l i te ra ture

Interesting facts about vacuum Sloan Instruments Corporation, USA, have recently issued a one- page data sheet describing the molecular conditions prevailing under the range of pressures from atmospheric down to 10 -~ torr. Molecular density, mean free path, distance between molecules and collisions per second are among the data given. As a conceptual aid, compara- tive figures are presented for an enlargement of 220 million times when oxygen or nitrogen molecules approach the size of baseballs. Basic equations for the calculation of molecular velocity, mean free path and mass of gas striking a surface are included. Copies may bc

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Pneumatic products C A Norgren Ltd of Warwickshire have announced their general price list, effective from the Ist January 1967. Price information on many new models are included. Among the products of this Company are filters and valve regulators for compressed air and vacuum lines.

C o m m e r c i a l n e w s

Pennsalt Chemicals declares quarterly dividend The Board of Directors of Pennsalt Chemicals Corporation at a meeting held in Philadelphia on 4 January declared a quarterly dividend of 25 cents per share on the common stock, and 62~ cents per share on the $2.50 cumulative convertible preference stock.

Pennsalt Chemicals Corporation is the United States parent of Pennsalt Ltd, Camberley, who manufacture and market the Sharpies and Stokes ranges of equipment for the chemical and process engineering, plastics, food and other industries. They also manu- facture and distribute special purpose chemicals. The Camberley company, as well as being the UK manufacturing organization and responsible for UK sales, is the headquarters of the organization which, working through associated companies, agents, and their own overseas staff, manufactures and sells Sharpies and Stokes equipment throughout Europe, Asia, Africa and Australasia.

Anglo/French:American initiative W P Butterfield (Engineers) Ltd of Shipley, Yorkshire, England have signed an agreement with Compagnie des Ateliers et Forges de la Loire (CAFL) at Firminy, France whereby the latter become sole licensees and manufacturers in the Common Market countries of Butterfield-designed cryogenic vessels. Butterfield vessels incorporate techniques developed by the American Cosmodyne Corporation, of