How Do Heat Alarms Work?

Written by abraham robinson | 13/05/2017

Heat alarms are devices that may be installed in addition to smoke detectors. Rather than detecting particles in the air (as smoke detectors do), they activate as a result of high temperatures.

Rate of Rise Detectors

Some heat detectors trigger only as a result of a rapid rise in temperature. They contain a thermometer that triggers an alarm in reaction to a rapid rise in temperature.

Fixed Temperature Detectors

Fixed temperature detectors react when the air around them reaches a certain temperature (they are usually set to 57.2 degrees C). They contain a thermometer that triggers the alarm when it reaches that temperature.

How They Work

Many detectors contain a small piece of metal that changes in size in response to air temperature. Higher temperatures cause it to extend, eventually bringing it into contact with another piece of metal completing a circuit and triggering the alarm.

Combination Detectors

Many detectors contain both rate of rise and fixed temperature sensors to increase their chances of accurately and quickly responding to a fire.

Electronic Detectors

Some modern detectors contain small electronic sensors which measure the air temperature and trigger a system when it reaches a certain point.

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.