Computerised security systems can use a wide variety of different sensors to detect intruders. There are pressure pads which trigger when walked on, infra-red sensors that can detect body heat, and air pressure sensors that can "hear" breaking windows.
Burglar alarms can use these sensors to track the progress of an intruder from one room to another. If this progress isn't seen, the alarm will not sound. This helps prevent false alarms.
|
