Presence Detector (PIR)


A PIR detector located strategically inside the protected area is an infrared „eye“ detecting any movement over its area.

PIR denomination comes from Passive Infrared, known as thermal infrared as well.

This is the natural radiation emitted by warm objects, i.e. the thermal radiation produced by a fire. Common objects’ extremities with normal temperatures and moving around us emit more passive infrared radiation than the background they  stand on. People, living creatures generally, and hot engine cars emit more radiation that PIR detectors can detect anytime (daytime and night time as well).

Passive infrared radiation does not have to be taken for the TV remote control infrared radiation. Passive infrared does not emit harmful radiation. All it does is „to see in the dark“.

Most people have heard of passive radiation used for movement detectors commanding automatic light turning on or opening stores’ doors.

Passive infrared radiation can also be used for various automatizations such as: light/air conditioning turning on/off, door opening/closing, alarm equipments,  presence detection, etc.

Passive infrared radiation is detected by the pyroelectric sensor. This sensor detects temperature changes up to a degree thousandth produced by a person’s 10m movement.

According to the protected area features, pyroelectric sensored detectors can be provided with different type of lenses: volumetric, pets, curtain or corridor type.

Some detectors also use microwave detection according to radar principle. They are used in high false alarm producing risk areas.


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