No discipline

Sensor Review

ISSN: 0260-2288

Article publication date: 1 June 2000



Loughlin, C. (2000), "No discipline", Sensor Review, Vol. 20 No. 2.



Emerald Group Publishing Limited

Copyright © 2000, MCB UP Limited

No discipline

No discipline

We have electronic engineers, chemical engineers, mechanical engineers, software engineers, physicists and even mechatronic engineers; but is anyone a sensor engineer? I am sure some readers would regard themselves as such, but I doubt if that was the title of the course they studied at college or university.

In fact as far as I know (please e-mail me if I am wrong), no one does a degree course in sensors. The reasons for this are fairly evident in that sensor technology covers so many other different fields (all of the above and more), that it may be considered impractical to teach it as a subject in its own right.

Just looking at this issue we have contributions using polymers, organic films, fibre optics, gas sensors and signal processing. Quite a mixed bag, but only a small sample of the technologies that we regularly cover in this journal.

A lot of emphasis is now being placed on having a multi-disciplinary approach to engineering projects. Concurrent engineering is one example where the designers, machine shops and marketing departments are meant to get round a table to help ensure that the designed product can be made and that customers will want it, before a single piece of metal is cut. Mechatronics is an amalgamation of mechanical and electronic engineering that aims to produce better machines than those emanating from either a mechanically biased or an electronic biased design team.

Sensor technology is crying out for an even broader perspective. For any given sensing problem there may typically be six very different but perfectly feasible solutions. They are likely to vary wildly in cost and ease of implementation, and each would have its own set of good and bad characteristics. The trick is to choose the best solution, and you only stand a chance of doing so if you are also aware of the other five.

Let us consider the measurement of stress and strain in a sailing boat mast. One solution, using fibre optics is well reported in our feature "Optical fibre strain sensing for practical structural load monitoring". How else could this problem have been solved? Thirty years ago about the only way would have been to bond an array of strain gauges to the mast and rigging and have a large number of necessarily fragile wires running back to precision amplifiers and chart recorders. This would be difficult under any circumstances but the chances of such a system working reliably in a force eight gale with salt water spray going everywhere are not too great.

CCD cameras could also be used to locate the position of special targets on the mast and measure bending. Again this might work under ideal conditions but at sea with vibrations shaking the camera, and the sails and sailors blocking the camera's view of the targets, the results are likely to be disappointing.

I can think of a few more possible approaches (not sure if I could manage six), but none improves on the method chosen by Smart Fibres. Had the marine engineers been unaware of the possibility of using fibre in this way then they would have been faced with either struggling with an alternative or deciding against the whole idea. I am sure that Smart Fibres experienced lots of problems and had numerous difficulties to overcome, but I am also sure that these would have been significantly worse if other approaches had been attempted.

The optimal application of sensor technology relies on the user having knowledge of a broad range of possibilities and the difficulties likely to be experienced in their application.

Clive Loughlin

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