Emerald Group Publishing Limited
Copyright © 2000, MCB UP Limited
Ultrasonic sensors can now be programmed in seconds, even in awkward locations
Plug-in tool means engineers can set thresholds remotely at the push of a button
Keywords Sensors, Ultrasonic, ABB
ABB Control's new remote programming tool (see Plate 4) virtually eliminates the problems of setting up ultrasonic position sensors - traditionally an awkward job. Ultrasonic sensors have near-immunity to dirty conditions and a long sensing range, but they can be difficult to set up because the instrumentation engineer must physically reach the sensor to set the thresholds. In many installations this is difficult or impossible.
Plate 4 ABB Control's new remote programming tool virtually eliminates the problems of setting up ultrasonic position sensors
The new programming tool simply connects via a 1.5m cable between the sensor and its connector cable; all that is needed are two button pushes to set maximum and minimum sensing values, then the unit can be removed. This solution is more accurate than the altemative of setting thresholds via potentiometers, which can "drift".
Conrad Slater, ABB Control's sensor specialist, expects that the new tool will lead to increased use of ultrasonic sensors: "They have many benefits", he says. "They can be used to detect position from any sound-reflective surface at a distance up to six metres - much greater than capacitive and inductive sensors - and unlike optical sensors, they are self-cleaning and immune to dust, so they can operate in harsh conditions."
Ultrasonic sensors determine position by measuring the time taken for an ultrasonic pulse to be reflected from the substrate. Output responds to changes in position typically within 100ms, and are linear to within 0.1 per cent. Resolution can be better than 0.2mm even at a sensing distance of several metres.
The output of ABB Control's ultrasonic sensors are automatically compensated for changes in ambient temperature. Shock and vibration performance exceed the EN 60974-5-2 standard, and the sensors have IP65 ingress protection rating.
ABB Control now has a range of 200 position sensors, sufficient to meet 80 per cent of system builder, OEM and end-user needs. They are available from ABB Control's Coventry distribution centre and from a network of distributors.
For further information please contact: Conrad Slater, ABB Control. Tel: +44 (0) 1203 368500; Fax: +44 (0) 368401 or Danny Dicks, Roger Staton Associates. Tel: +44 (0) 1628 487222; Fax: +44 (0) 1628 487223.