Alarm sensor

In telecommunication, the term alarm sensor has the following meanings:

1. In communications systems, a device that can sense an abnormal condition within the system and provide a signal indicating the presence or nature of the abnormality to either a local or remote alarm indicator, and (b) may detect events ranging from a simple contact opening or closure to a time-phased automatic shutdown and restart cycle.

2. In a physical security system, an approved device used to indicate a change in the physical environment of a facility or a part thereof.

3. In Electronic Security, sensors can detect any number of abnormal or normal situations. Motion detectors can be used to detect motion, or lack there of; Glassbreak detectors can detector the sounds made by breaking glass. Other sensors include: door / window contacts, carbon monoxide detectors, smoke detectors, dangerous gas sensors, liquid sensors, level sensors, temperature sensors and more. Relays can also be used to supervise power in power critical environments.

Note: Alarm sensors may also be redundant or chained, such as when one alarm sensor is used to protect the housing, cabling, or power protected by another alarm sensor.

Source: from Federal Standard 1037C and from MIL-STD-188