Vacuum News

dipping compound, araldite and others, and then, as a second operation using the same equipment, potting or encapsulating electronic circuits, specimens etc. in the liquid whilst under vacuum.

The special feature of this equipment is the facility to cast in epoxy resin, araldite etc., which has a limited bench life, having

been mixed with hardener. The special liquid inlet valve has a liner and connecting pipes cheap enough to be expendable, which can be replaced after each operation, if needed.

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Expansion of M RC sales force Following a substantial increase in sales of MRC High Purity metals, alloys and ceramics. Keith Millns has joined Materials

Research Company Ltd as Technical Sales Engineer. Mr Millns has previously been employed as a Technical Representative with Thermal Syndicate Ltd. and Sales Engineer with Bush Beach Engineering. His experience in selling high quality materials to the

electronics industry will be invaluable in developing fully the expanding market for MRC materials. Mr Millns’ territory will cover the Midlands, the North of England and Wales, and he will be responsible for the full range of MRC

materials, and film deposition equipment.

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Merger of Stereokautschuk with BWH Bayer AG, Leverkusen, and Chemische Werke Hiils AG, Marl, have merged their subsidiary Stereokautschuk-Werke GmbH Et Co. KG,

Leverkusen/Marl, in which both had a 50 per cent interest, with Bunawerke Hills GmbH (BWH), Marl. The purpose of this step, by which advantage has been taken of

the Transformation Tax Law, parts of which cease to be valid at the end of 1972, was to simplify the co-operation of the two parent companies in the field of rubber. In connection with the merger the capital stock of Bunawerke

Htils GmbH will be raised by DM 8 million to DM 50 million. The parent companies will continue to hold 50 per cent of each BWH’s capital stock. Another effect of the change is that the shares

hitherto held for Bayer by the holding company Synthesekautschuk-

Beteiligungsgesellschaft mbH, Leverkusen, will be transferred to

Bayer AG itself.

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A new generation of low cost computers The newest generation of electronic components can cut the cost

of an effective computer system to as little as f500. This is one of the conclusions of a 6-month study of components, called microprocessors, carried out by a team at the Electrical Research Association, at Leatherhead near London.

Their report is published by Ovum as ‘Microprocessors-an ERA assessment of LSI computer components’, at f29. It defines a microprocessor as a computer processing unit implemented in large scale integration (LSI) electronics. This means having all the essential functions of a minicomputer etched into a small chip of silicon and mounted in a package 0.75 in. (20 mm) long. ‘Microprocessors open up a completely new vista of computer applications’, says Dr David Turtle who heads the team working within the ERA Computers and Automation Division. ‘Their low cost will make it possible to use computing power in places which would never have been considered before.’ Turtle believes the first widespread application will be in computer peripherals, because ‘the computer industry is already showing the most advanced understanding of the value of these components and how to use them’.

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‘Next, the automation industry will begin to use microprocessors

as replacements for conventional hard-wired logic equipment, or where minicomputers have proved too expensive. And in the long term they will go Into consumer equipment-doing such lobs as, for example, controlling all the warning and emergency systems in

a car.’ The advantages of microprocessors in cost and other respects promise to be big. ‘In typlcal situations a microprocessor can replace perhaps 100 MSI (medium-scale integration) packages and

result in lower component costs, lower wiring costs, lower systetn design and development costs, smaller size, higher reliability, and considerably more flexibility when modifications are required’, says

the report. The best known microprocessor available today, the Intel 8008, costs only f26 per unit in quantity orders. It includes in the one package all the essentials of a miniature computing unit. including

working registers and ‘scratchpad’ memory. But it has to be surrounded with external memory and other components to carry out a complete function. Other manufacturers who have so far announced microprocessors include American Micro-Systems, Fairchild, Microsystems

International, and National Semiconductor. The American Micro-Systems 7200, which will probably cost fl20 in quantity, promises, according to the report, to be the most powerful of this

generation of microprocessors. and perhaps the only one immediately to compete effectively with minicomputers. David Turtle and his colleagues have been working with an Intel 8008 microprocessor in the laboratory for over 6 months, and report that the component performs very well, but with virtually no software or documentation available. the team had to

start from scratch in learning how to use the device. In addition to undertaking laboratory work and evaluating manufacturers’ specifications for other microprocessors, the team conducted a series of real-life applications studies, one of which concerned a system for automating the microwave measurement of

properties of materials. Using a microprocessor they designed a system to do the lob at an estimated hardware cost of f 567- against a comparable cost using a mlnicomputer of well over

f2.000. Electrical Research Association

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Air leak prevention Arno Foam Tape has been adopted by Colt International Ltd. as an air sealant for their new range of Turbo-static oil and gas-fired warm air heaters, as well as for various ventilation equipment. The Foam Tape, L51, is produced by Arno Adhesive Tapes Ltd. Hythe, Southampton.

Colt’s unique heating system revolves around their Turbo-static heaters. Each heater comprises a specially designed combustion chamber which mixes and burns an oil/air mixture. The lower section of the heater houses a powerful centrifugal fan, which

blows air upwards past the hot surfaces of the heat exchanger. Subsequently the heated air is fed through louvred openings to the room requiring heat.

The top half of the unit is therefore subject to considerable internal pressure and the outer casing panels especially. Joints between these panels require to be airtight, for leakages would be wasteful and annoying to people working in the vicinity. Arno Foam-Tape is being successfully used to seal the joints between these outer casing panels. By preventing metal-to-metal contact, its cushion effect eliminates any danger of vibration noises being set up between the panels. Constructed of an open cell polyurethane foam and a pressure sensitive adhesive, L.51 provides an easy to apply, reliable answer to many sealing problems. The tensility of the tape makes it ideal

for absorbing slight movement in the heater casing panels. Arno Adhesive Tapes Ltd produce a wide range of p.u. foam.