What is the purpose of masking in PIRs?

Masking in Passive Infrared Sensors (PIRs) serves a crucial purpose in enhancing their effectiveness by blocking potential false alarm sources from the sensor's field of view. PIRs detect infrared radiation emitted by objects, typically humans or animals. By using masking, you can create barriers or shields that cover specific areas where movement might trigger false alarms—such as areas with heat sources like vents, sunlight, or even pets.

This ability to limit the sensor's field of view helps ensure that the PIR only responds to the desired targets, thereby reducing the likelihood of unnecessary alerts and improving the overall reliability of the intrusion detection system. Masking can be especially important in environments with various heat-emitting objects or activities that might otherwise confuse the sensor. This focus on enhancing accuracy and reducing false positives is why masking is an essential technique in the design and deployment of PIRs.