Vacuum News

Minni ‘A’ vacuum pump

Leybold believe that their new Minni ‘A’ rotary-vane vacuum

pump is the only one in its price range to offer a gas ballast valve to assist the removal of condensable vapours. It is a laboratory pump with an integral 240 V drive motor, and has a pumping

speed of 15 I/m, producing an ultimate pressure of 0.8 torr. It

can also be used to produce over-pressures of up to 7 lb/in*.

The Minni ‘A’ has a built-in pressure relief valve to protect the

pump from high over-pressures. It also protects the vacuum

pump, which can be switched on and off without the necessity for taking special precautions. It is easily portable, weighing only

an MD6 variable leak valve with beam current proportronal to the pressure in the ion source. Its chief applications are sputtering,

ion beam polishing, determination of depth concentration profiles, and specimen cleaning in surface physics investigations e.g. LEED, Auger, ESCA etc.

Model AG3 produces beam energies variable up to 2.5 keV, and

includes beam focussing and deflection facilities. Beam current is

proportional to the ion source pressure, and this gun can operate at up to IO -4 torr of argon.

Its applications are primarily surface analysis by secondary ion

spectroscopy and secondary ion mass spectrometry (SIMS). Vacuum Generators Ltd

Circle number 41 on Reader Enquiry Service card

Spectromel@ mixtures

Johnson Matthey Chemicals Ltd have introduced a useful extension to their range of high purity materials specially prepared for the analyst.

The new range, marketed under the name Spectromel@, has been developed for the preparation of standards for use in

semiquantitative emission spectrographic analysis, and consists of three mixtures : Mixture 1 : contains 53 common elements, for use in general analysis

Mixture 2: contains 8 precious metal elements Mixture 3: contains 16 rare earth elements including scandium

and yttrium. Johnson Matthey Chemicals Ltd

Circle number 42 on Reader Enquiry Service card

New Minni ‘A’ laboratory vacuum pump from Leybold-Heraeus.

6 kg (13.2 lb), and has a carrying handle on top. The single-phase

electric motor is rated at 70 W for continuous use at atmospheric pressure. With its gas-ballast facility it is ideal for pumping gases with a high vapour content.

Leybold say that this handy pump will replace water-jet pumps, where water consumption is an important factor. They

recommend it for general-purpose laboratory use for evacuation, filtration and distillation, and also for use in dental labs and

jewellery casting. Leybold-Heraeus Ltd

Circle number 40 on Reader Enquiry Service card

Argon ion guns Vacuum Generators Ltd announce further additions to their range of ion guns. Three models are now available.

Model AGI produces a beam of argon ions with beam energies variable between 194 and 494 eV. The gun comprises an ion source of similar construction to a hot cathode ion gauge, and produces a 10 mm diameter beam with a maximum current of 1 PA at 10 -4 torr argon pressure. It operates in a chamber flooded with argon to the desired pressure, the argon pressure determining the beam current. Its main application is specimen cleaning for surface physics.

Model AG2 produces beam energies variable up to 10 keV, beam currents up to 100 PA and beam diameters variable from 5 mm to 20 mm. The argon is admitted directly to the ion source through

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The new Balzers quadrupole mass spectrometer QMG511- an instrument speaking the computer language

Faced with two possibilities, that of adapting a commercial quadrupole mass spectrometer with a high cost interface unit to

a computer, or of designing a quadrupole mass spectrometer which uses the computer language, Balzers chose the second.

This solution guarantees a simpler, faster and more effective

transfer of data logging and quadrupole mass spectrometer control.

Balzers High Vacuum Ltd Circle number 43 on Reader Enquiry Service card

Ultra sensitive pneumatic valve actuator New from the Schrader Fluid Power Division, Cannock, Staffs, is an ultra-sensitive actuator, which extends the flexibility of the

company’s & in. midget spool valve range.

The actuator has been developed specifically to cater for the increasing number of advanced pneumatics applications which require a very sensitive trip action, and utilises a wire sensor or ‘whisker’ to operate either 3-way or 4-way Q in. midget spool valves.

The wire sensor is normally part of the valve but it can be removed from its housing and attached to the end of a nylon tube. Providing the tube is no longer than 12 in., there is very little difference in the valve response time. It can also be bent or formed by hand to enable it to be fitted into a confined space or triggered by awkwardly-shaped components.

Schrader Fluid Power Circle number 44 on Reader Enquiry Service card