"Alan" wrote in message
...


In some respects yes, if taken to the extreme , but also regard a
regular calibration in the same way a road vehicle MOT test. Many faults
are not identified until someone else checks out the equipment.


Not sure if that's a good analogy. A good car mechanic will have some
sympathy with the car and sort important things out before an MOT. Recovery
vehicles are exempt from MOTs.