Question

After which frequency range, pneumatic measuring system is not correctly measured displacements?

(a) 5 cycles/second

(b) 4 cycles/second

(c) 3 cycles/second

(d) 2 cycles/second

I got this question in an international level competition.

My question is taken from Pneumatic Comparators in chapter Comparators of Engineering Metrology

Answer 1

The correct choice is (d) 2 cycles/second

Explanation: Pneumatic measuring system can’t measure displacements correctly after 2 cycles/second because its response spend is slow. Its response is slower than electrical systems. Response time of back pressure type can be improved by using filled system pressure gauge.