The Intruder Alarm Sensors This infrared light is given off by a moving object or person that emits heat. Door and window sensors are used to detect when a door or window is opened. These can be connected to the control panel or a keypad, and can also be used with other sensors to trigger an alarm.
A security alarm is a system designed to detect intrusions, such as unauthorized entry, into a building or other areas, such as a home or school. Security alarms protect against burglary (theft) or property damage, as well as against intruders. Examples include personal systems, neighborhood security alerts, car alarms, and prison alarms.