Which of the following is a desirable characteristic of an instrument?

Solution (By Examveda Team)

Instruments used for process control and measurement are expected to provide accurate, reliable, and consistent readings of process variables such as pressure, temperature, flow, and level.

A desirable characteristic of a good instrument is high fidelity, which means the instrument is capable of accurately reproducing the input signal without distortion or delay.

High fidelity ensures that the output of the instrument truly represents the measured variable and responds correctly to rapid changes in the process conditions.

On the other hand:

High drift (Option A) is undesirable because it causes the instrument reading to change with time even when the measured variable remains constant.

High measuring lag (Option C) is also undesirable because it delays the instrument’s response to changes in the input signal, reducing accuracy in dynamic systems.

Poor reproducibility (Option D) means the instrument cannot produce the same reading under identical conditions, which affects reliability and consistency.

Therefore, the most desirable characteristic of an instrument is high fidelity.

Hence, the correct answer is Option B: High fidelity.