Calibration drift causes are which of the following?

• A. Sensor aging is one cause of drift; Environmental conditions and electronics degradation are not involved.
• B. Environmental conditions are the sole cause of drift.
• C. Sensor aging, environmental conditions, and electronics degradation contribute to drift.
• D. Zero calibration checks cause drift.

Answer: (C)

Calibration drift is the gradual change in a sensor’s output compared to the true value over time. This happens because several factors wear on the system: aging of the sensing element, degradation or drift in the electronic signal path, and changing environmental conditions such as temperature, humidity, vibration, or contaminants. Each factor can alter the sensor’s response, affecting both its offset and gain, so drift accumulates as time passes. Zero calibration checks don’t cause drift; they’re used to detect and correct drift when performed. That’s why the option recognizing sensor aging, environmental conditions, and electronics degradation as contributing causes is the best choice.