Telemetry Speeds Track-testing
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T°aid the track-testing of prototype vehicles and components. Sir W. G. Armstrong Whitworth Aircraft, Ltd.. have developed an automatic radio link which can transmit data obtained from strain gauges, thermocouples and similar measuring instruments on a vehicle in motion to a remote recorder stationed inside a building or, perhaps, in a caravan.
One type of equipment which has been demonstrated costs between £2.000 and 1:5.000, depending upon its complexity, and can record the readings of up to 23 instruments. The radio link handles 250,000 signals per minute so that, in effect. readings are recorded continuously.
An ultra-high-frequency, interferencefree wavelength is used, and the radio can have a ranee of several miles. The prototype unit employed a low-powered transmitter to give a two-mile range. Recording is carried out by either automatic ink pens or ultra violet photographic charts to give graph-type presentation. The readings are displayed also on meters or a cathode-ray oscillograph to allow the test engineer to observe the result of tests as they are carried out.
As the engineer is in contact with the driver of the vehicle through a V.H.F. radio-telephone link, he can indicate further tests required or warn him of imminent failure in any component under observation. Similarly the driver can communicate peculiarities in the behaviour of the vehicle.
Thi . equipment carried in the vehicle is compact and weighs 30 lb. It can be placed on the seat beside the driver, who can switch it on or off as required. Power for the transmitter is obtained from the vehicle's battery. Transistors are employed in the gear as they are unlikely to be affected by the shocks which the vehicle-borne unit will have to encounter in service.
It is claimed that by using this telemetering device designers get a continuous record of performance from more sources and much faster than can be obtained with previous equipment. This could cut the development time for prototypes and reduce production modifications, One vehicle manufacturer has had the gear installed in a test car already,