How Does a Fire Detector Work?

A fire detector works by detecting smoke and/or heat. These devices respond to the presence of smoke or extremely high temperatures that are present with a fire. After the device has been activated, it will send a signal to the alarm system to perform the programmed response for that zone.

Since a fire detector usually works by detecting smoke and/or heat, and not actual fire, these devices are not usually called "fire detectors". Instead, these devices are more appropriately called "smoke detectors" and "heat detectors". Some of these devices are single-function devices that will only detect either smoke or high temperatures. However, other sensors are multi-function, and they will detect the presence of both smoke and high temperatures.

Multi-function devices are usually the most effective when it comes to detecting a fire. However, single-function devices are typically less expensive. Additionally, multi-function devices might not be appropriate for every area. For example, there may be a room inside the home where smoke is commonly present. This could include a kitchen or a designated room for smoking herbs. For these areas, a single-function heat sensor may be more appropriate than a dual-function smoke and heat detector.

Once a smoke and/or heat detector has activated, it will send a signal to the alarm system to perform a predetermined response. Many users will set up their system to immediately send out a distress signal to a central monitoring station as soon as the device activates. This will ensure that the fire department is sent out to the premises as soon as possible. However, it is also common practice to require that the sensor receives verification of a fire before it sends an alert to the central station. This usually involves having the sensor activate twice within a short period of time. By programming the sensor this way, the user can prevent false alarms.

Additionally, many of the newer "fire detecting sensors", such as the Honeywell 5800COMBO and the Honeywell SiXSMOKE, are able to use infrared vision to detect the flickering of flames that are associated with fire. In the future, it may be possible to have a true "fire sensor" that specifically looks out for actual fire, rather than the smoke and heat that are associated with it.