|Passive IR for Intruder Detection|
PIR is a common device deployed in intruder detection security systems. It senses human body temperature and can differentiate between motion of human body and movement of leaves outside the window.
Some cameras have incorporated PIR as a means of reducing the uncertainty for motion detection purposes. For example, the camera will not start motion detection when the leaves outside the window move and will start motion detection if the PIR confirms the intrusion of human into the area of monitoring.
Do not be confused between IR filtering, IR LED and Passive IR as far as camera motion detection techniques are concerned.