Question

Discuss the importance of implementing measures to militate against electrical interference (electrical noise) in a modern electric instrumentation system.

Answer 1

Electrical noise is an undesirable signal which would distort our original signal, leading to wrong measurements. Earlier it was thought that noise generally averages out and so true readings can be obtained. But lately, new instruments are appearing with lower levels of voltage, and when we try to achieve increased resolution with these devices, noise presents a problem, since now we are trying to differentiate between voltage levels which are several orders of magnitude lower than the noise levels. These noises are very unpredictable. Our recording equipments use amplifiers which cause loss of sensitivity and dead-banding in presence of noise. The amplifier saturation occurs, when the operating point of amplifier shifts to non-linear region.