What is the term for the difference between the on and off points of proximity sensors?

• A. Deadband
• B. Hysteresis
• C. Tolerance
• D. Latency

Answer: (B)

Hysteresis is what happens when a proximity sensor uses different turn-on and turn-off points. As a target approaches, the sensor switches on at one distance; as the target moves away, it doesn’t switch off at the same distance but at a separate, typically farther, distance. That gap between the two thresholds creates a history-dependent switch, so the output won’t chatter if the object sits near the threshold or if there are small vibrations or noise. This behavior is deliberate to ensure stable operation.

Deadband is related in that there is a region where changes don’t affect the output, but the standard term for the difference between the turn-on and turn-off points is hysteresis. Latency is the delay between input change and output response, and tolerance refers to allowable variation in measurements, not the switching thresholds themselves.