Intrusion alarms are sensors that detect break-ins or forced entries into your facility.  Intrusion alarms come in many different types.  Door contacts monitor doors; glass break detectors assure an alarm is sounded if a window is broken; passive infrared sensors respond by sensing body heat.  Well designed security systems are engineered in such a manner to employ the best sensors fitting the requirements of your particular installation.

A good security system design focuses on high functional reliability and immunity to false alarms, and should incorporate modular components and simple operating elements.