Instrumentation Monthly Test | Measurement | Control
Until recently, Bristan, a UK manufacturers of bathroom taps and showers, carried out tests by continuously operating the taps and controls using a pneumatically operated test rig with fixed stop positions for the rotary motion. With this arrangement, however, little allowance was made for any increase in operating torque that occurred during testing and it could not accommodate the effects of wear in, for example, the rubber washers used in taps.
For help with devising a better method of testing, Bristan approached ADI, a company that it knew had wide experience in developing specialist test equipment. After carefully analysing the application requirements, ADI proposed a completely new test rig, which would be driven by servomotors rather than pneumatic cylinders, as this would allow much more accurate and consistent control to be achieved.
In addition, instead of using fixed stops for the rotary motion, the new test rig would be arranged to stop when the torque in the drive system reached a preset value. This arrangement was preferred as it would not only compensate automatically for wear in the component under test, but would also more accurately reflect the real life operation of the component, since users typically stop tightening a tap or rotating a control when a certain level of ‘stiffness’ is reached.
While the design of the new test rig was in many respects straightforward, ADI did face one particular challenge – how to measure the torque developed by the drive system accurately and in real time, so that the stopping points could be determined.
The company then discovered the TorqSense range of sensors from Sensor Technology.
“These versatile sensors were exactly what we needed,” said Jeff Lowe of ADI. “They’re tiny, so they were easy to accommodate on the test rig, they’re dependable, and they provide very accurate results in real time, even at the very low torque levels we are interested in. Also, because they’re not tied to unnecessary extras like speed monitoring, they were a very cost effective choice for this application.”
“At Bristan we pride ourselves on our rigorous test procedures to ensure that our taps and showers are of the highest quality,” said Adrian Lowe, test laboratory manager at Bristan. “Our previous test rig, while fit for purpose, didn’t allow for such thorough and accurate testing. The new rig is an invaluable tool in ensuring that we continue to maintain the high quality for which our products are known, and also for helping us develop new and groundbreaking products in the future.”
