Question

Change in signal over long period of time is called

• A. \( \text{Noise} \)
• B. \( \text{Offset} \)
• C. \( \text{Hysteresis} \)
• D. \( \text{Drift} \)

Hint:

Drift is a common issue in many electronic systems and sensors. It can significantly affect the accuracy of measurements over extended periods. Regular calibration and using components with good long-term stability are crucial to minimize drift. In some applications, software compensation algorithms are used to counteract the effects of drift.

Answer 1

The Correct Option is D

1. Noise: Noise refers to unwanted random fluctuations or disturbances that obscure or interfere with a signal. It typically has a high-frequency component and is not usually characterized as a change over a *long period*.
2. Offset: Offset is a constant difference or bias in a signal from its true zero or reference point. It's a static error, not a change that evolves over time.
3. Hysteresis: Hysteresis is the dependence of the output of a system not only on its current input but also on its past inputs. It's often seen as a lag or memory effect, where the output for a given input differs depending on whether the input was increasing or decreasing. It's not a general long-term change in signal.
4. Drift: Drift is a slow, gradual change in the output of a system or sensor over time, independent of any change in the input. This change can be due to temperature variations, aging of components, or other environmental factors, and it specifically occurs over a *long period of time*.

Based on these definitions, the term that best describes a change in signal over a long period of time is drift.