Linear TMD-90 Supervised Passive Infrared Motion Detector

Dual-element pyroelectric sensor. The TMD-90 Supervised Passive Infrared Motion Detector is a passive infrared (PIR) motion detector with a built-in supervised, digitally-coded radio transmitter designed for security applications. The PIR detects motion in its detection pattern by measuring the infrared emission levels of objects that it sees. If the infrared levels change quickly, as when a person moves across the detection pattern, the PIR will recognize the change as an intrusion.