What is sensor nonlinearity vs random noise?

• A. Nonlinearity is random fluctuations; noise is systematic deviation.
• B. Nonlinearity is a systematic deviation from linearity; noise is random variability.
• C. Nonlinearity is caused by sensor aging; noise is caused by environmental temperature.
• D. Nonlinearity and noise are identical phenomena.

Answer: (B)

The main idea is the difference between a deterministic distortion of the sensor’s response and random variability in measurements. Nonlinearity means the output is not proportional to the input; the sensor’s transfer function bends or saturates, so the relationship between input and output deviates from a straight line in a systematic, repeatable way. This kind of distortion can be characterized and corrected with a calibration curve or compensation, and it depends on the input level.

Random noise, on the other hand, is unpredictable fluctuations around the true value caused by various stochastic processes in the sensor and electronics. It does not form a fixed curve with input and can be reduced by averaging or filtering, but it won’t produce a consistent non-straight transfer relationship. So the distinction is: nonlinearity is a systematic deviation from linearity; noise is random variability.