Which environmental factor should be minimized to reduce false alarms in PIR systems?

Minimizing bright white lights is crucial for reducing false alarms in Passive Infrared (PIR) systems because these sensors operate by detecting changes in infrared radiation, which is emitted by warm objects, including human bodies. Bright white lights can interfere with the infrared detection process by either overwhelming the sensor with additional heat or altering the ambient temperature of the area, leading to incorrect assumptions that movement is occurring. This can cause the system to falsely trigger an alert, as it may misinterpret fluctuations in infrared signals caused by rapid changes in lighting conditions rather than actual motion.

In contrast, factors like installation height, wall color, and detector location are important in their own right but do not directly relate to the interference from light sources. Installation height may affect the detection range, wall color could influence the ambient temperature but not as significantly as bright lights, and while the location of the detector is vital for optimizing its effectiveness, the presence of bright white lights is a more immediate source of interference that can easily lead to false alarms.