Vacuum news

The Stoptester B-36 event and production recorder Barbie Engineering have introduced a new 36-channel Stoptester B-36 a desk-top shaped device which may monitor as many as 36 individual activities or the operating conditions of up to 36 machines or stages of a process. The Stoptester may also record plant production rates or quantities produced or monitored. Each channel is normally controlled by a simple contact or microswitch on the machine or plant moni- tored but a range of special transducers have been developed for other applications. In alternative models, a counter is con- nected to each channel allowing recording of the number of times, or the total length of time, a condition has occurred, or the quantity of production in suitable con- tinuous or batch processes. Indications are easy to read with no running out of ink and no smudging, since a novel method of recording is employed resulting in a clear, reliable record on an inkless strip-chart. The Stoptester is recommended for: timing the occurrence of any condition; monitor- ing the operation of unattended equipment; providing a permanent record of the func- tioning of complete plant units; production control and job costing: and totalling, on the counter, the duration of a condition. Indications may be coded automatically or by the push-button operated Stopselector, to show special conditions.

The 36 and 12-channel models were exhibited at the Instrument Electronics and Automation Exhibition at Olympia, London, 13th-18th May 1968, the B-36 appearing for the first time in this country. Barbie Engineering, UK Circle nutnhcr 54 on Render Enquiry Service card

Automatic precooling cold trap filler The Cryogenics Division of International Controls Corporation have introduced a new liquid nitrogen level control system designed for automatic filling of coId traps with minimal trap blow-out. The IOOLS system operates on a two-stage control system consisting of a pre-cooling of the transfer line prior to initiation of the cold trap refilling.‘Two sensing elements are in- corporated into a flexible stainless steel sheathed probe. One element acts as the lower limit and is located at the tip of the probe while the other, the upper limit, is located at a fixed distance from the lower limit. When the liquid level in the trap falls below the tip of the probe, the controller

Eitnac’s argon-ion laser

Barbie’s Stoptester B-36

activates the pre-cooling circuit initiating flow through a pre-cooling valve and main- taining this flow until the valve tempera- ture reaches about 80”K, as sensed by the temperature switch. The filling mode is then automatically switched on and flow to the cold trap proceeds until the liquid nitrogen level reaches the upper limit of the sensing probe. The system comprises a controller, a level sensing probe, a temperature switch and two solenoid valves. The IOOLS is in-

tended for use in liquid nitrogen trapped high vacuum systems requiring continuous operation in such applications as thin film deposition, electronics, space simulation and materials research. International Controls Corporation, Cryo- genics Division, USA Circle nutnhcr 55 ott Reader Enquiry Service card

Inert atmosphere welding system Vacuum/Atmospheres Corporation, of California, USA, reports the completion. delivery and acceptance of their new HE- 113-125 Custom Vacuum Welding Cham- ber. The HE-113-125 is being used by a major manufacturing corporation for fabri- cation of components which require an inert atmosphere for the welding of stain- less steel, titanium and titanium alloys, tungsten, molybdenum and tantalum. The completed system was demonstrated before acceptance by the welding of various alloys with no discolouration or other signs of oxidation.

The main chamber provides a working area 45 inches in length Y 33 inches in height x 30 inches in depth. All areas in the dry box are within normal arm’s length from the front work station. One set of TIG welding feed-throughs is provided and semi-automatic welding equipment can be mounted in the chamber. The pneumatic operated welding shield on the HE-I 13-125 is raised and lowered by a foot switch. Other features include a full length, hinged and sealable door on the left side of the chamber in addition to 2 ante-chambers (air locks)-one at each end of the work chamber. The entire interior of the dry box is illuminated by exterior lamps to elimi- nate shadows.

A standard HE-373 BIN Dri-Train Gas Purification System is used to maintain the integrity of the inert atmosphere for the welding operation. The Dri-Train is re- cessed I5 inches to provide adequate “knee room” for the operator. The gas in the system is cooled prior to its return to the work chamber. The HE-113-125 is constructed of 6061S-T6 aluminium alloy. Vacuum/Atmospheres Corporation, USA Circle number 56 on Reader Enquiry Service card

The HE- 113- 125 welding chamber

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