Some smoke detectors provide a field adjustment of sensitivity; they must have an adjustment range of not less than how much per foot of obscuration?

The requirement for smoke detectors that provide a field adjustment of sensitivity is mandated to ensure that they perform effectively in various environments and conditions. Sensitivity is often expressed in terms of obscuration, which relates to how much smoke is present and how it affects the detector's ability to identify a fire condition.

The adjustment range of not less than 0.6% per foot of obscuration is significant because it provides a balance between being sensitive enough to detect smoke from a fire while not being overly sensitive, which could lead to false alarms. This specific calibration allows for adequate flexibility in maintaining the detector's performance across different installation scenarios, such as areas with high levels of dust or humidity, where smoke detectors might otherwise trigger unintentionally.

This standard emphasizes the importance of maintaining a reliable and effective smoke detection system, thereby enhancing life safety and property protection. By adhering to the 0.6% adjustment requirement, technicians can ensure that the smoke detectors will function as intended, providing timely alerts in the event of a fire while minimizing nuisance alarms.