16 Alarm Detection and Emerging Video Technologies
Alarms are the mainstay of security. The oldest security systems involved a public responsibility of citizens to stay awake all night and patrol in shifts, calling out for help if any threat was discovered.
There are three basic types of detection systems:
Alarm detectors may be used indoors or outdoors. Indoor applications can be of any type. Outdoor detectors are most commonly used on the perimeter, although there is some use of volumetric detectors. ...