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.