Motion detector

Description

A device that is used to detect movement. Some motion detectors, such as the passive infrared detector (PIR) use an infrared sensor to monitor an area for heat sources. Other detectors use ultrasonic sensors. Many home systems combine ultrasonic and infrared detection. Older style motion detectors use a light beam/ detector combination that sets an alarm when the path to the detector is blocked.

Synonyms and Related Terms

Bewegungsmelder (Deut.); dtecteur de mouvement (Fr.); detector de movimento (Port.)