fire will affect its environment in many ways. Fire detectors attempt to recognize these changes and respond with an alarm. Fire detectors respond to heat, particulates (smoke), or radiant energy. Heat and smoke detectors are the most common, although detectors that respond to radiant energy are used where extremely fast response is critical. A more detailed discussion of fire detectors can be found in the NFPA Handbook.
Certain fire detectors maybe used for detection and alarm only, or maybe utilized to actuate a fire suppression system and/or shut down equipment. Detectors should not be considered a substitute for suppression systems where those systems are appropriate.