What is a common method to reduce false alarms from PIR sensors?

Using masking to block irrelevant sources is an effective method to reduce false alarms generated by Passive Infrared (PIR) sensors. PIR sensors detect changes in infrared radiation, typically emitted by objects in their field of view. When these sensors are exposed to non-human sources of heat, such as pets, moving vegetation, or heat from machinery, they can trigger false alarms.

By strategically masking certain areas where these irrelevant sources are located, the sensor becomes less likely to pick up signals that could cause it to activate unnecessarily. This technique helps to ensure that the sensor focuses on the intended targets, like human movement, rather than extraneous factors that could lead to false positives. It is a practical approach to enhance the reliability of the PIR sensor without altering its inherent sensitivity settings or requiring additional user training, which might not address the root of the issue as effectively.