Noun

Singular fire alarm

Plural fire alarms

fire alarm (plural fire alarms)

1. An electromechanical or electronic bell, klaxon, chime, horn, speaker, strobe light or other device which warns people in a building of a possible fire or other condition requiring evacuation.
2. The sound or other warning made by a fire alarm.
3. (firefighting) An emergency response to a fire by the fire department with manpower and equipment.
   • A four fire-alarm fire ripped through a row of 2.5 story frame dwellings during the early morning hours

An automatic fire alarm system is designed to detect the unwanted presence of fire by monitoring environmental changes associated with combustion. In general, a fire alarm system is either classified as automatic, manually activated, or both. Automatic fire alarm systems can be used to notify people to evacuate in the event of a fire or other emergency, to summon emergency forces aid, and to prepare the structure and associated systems to control the spread of fire and smoke.

Design

After the fire protection goals are established - usually by referencing the minimum levels of protection mandated by the appropriate model building code, insurance agencies, and other authorities - the fire alarm designer undertakes to detail specific components, arrangements, and interfaces necessary to accomplish these goals. Equipment specifically manufactured for these purposes are selected and standardized installation methods are anticipated during the design. In the United States, NFPA 72, The National Fire Alarm Code is an established and widely used installation standard.