According to UL, how many steps can be taken before a motion detector should activate?

According to UL, how many steps can be taken before a motion detector should activate?

• A. Four steps
• B. Three steps
• C. Five steps
• D. Two steps

Answer: (A)

Think about how UL expects motion detectors to respond during testing: a detector should reliably identify motion as a person moves through its coverage, yet not be so sensitive that brief, incidental movements trigger false alarms. The standard walk-test threshold is four steps. That means, in typical installations, once a person has walked four steps through the detector’s field, the device should activate. This provides a consistent, repeatable measure of sensitivity across different rooms and mounting heights. If you tested with fewer steps, three or two, you might miss some legitimate intruder paths or fail to verify the detector's full range. Conversely, requiring five steps would indicate a higher activation threshold than UL intends for standard detectors, potentially delaying alarms in real scenarios. So four steps reflects the balance UL expects for reliable detection without excessive nuisance alarms.

Think about how UL expects motion detectors to respond during testing: a detector should reliably identify motion as a person moves through its coverage, yet not be so sensitive that brief, incidental movements trigger false alarms. The standard walk-test threshold is four steps. That means, in typical installations, once a person has walked four steps through the detector’s field, the device should activate. This provides a consistent, repeatable measure of sensitivity across different rooms and mounting heights. If you tested with fewer steps, three or two, you might miss some legitimate intruder paths or fail to verify the detector's full range. Conversely, requiring five steps would indicate a higher activation threshold than UL intends for standard detectors, potentially delaying alarms in real scenarios. So four steps reflects the balance UL expects for reliable detection without excessive nuisance alarms.