Optimisation et Evaluation d'un Systeme D'Alarme D'Intrusion Infrarouge (Optimization and Evaluation of an Infrared Intrusion Alarm System),

A passive infrared intrusion alarm system was modified and evaluated for its effectiveness to detect the presence of an intruder in a restricted area. the system consisted of an optical head gathering the infrared radiation coming from surrounding objects and their background onto a pyroelectric detector by means of a rotating and spherical focussing mirrors. The optical head was connected to an electronic circuit which compared successive scans to detect any significant changes in the collected radiation.