Kistler's Type 4520A sensor for measuring torque on shafts rotating at up to 10,000 rpm uses frequency modulation to transmit the torque signal from the rotating shaft without contact and convert it into an analogue signal. This system is considerably more reliable than slip-ring signal transmission which can suffer signal loss due to dirt and wear on the slip-rings. In the past, contactless sensors have been more expensive than slip-ring types but this design costs about the same as inferior slip-ring types.
The sensor has a TTL speed signal at 60 pulses/rev. and an external 100 per cent range check input. Ten units cover the range from 1 to 1000Nm, all with standard +/-10V signal output, and 150 per cent overload capacity. It is suitable for static and dynamic measurement of torque in assembly, for quality control in production and in laboratory applications. Priced at about £1500, the Kistler Type 4520A strain gauge torque sensor represents exceptional value for money.
More information about the Type 4520A sensor can be found at www.kistler.com.