A fire alarm system has a number of devices working together to detect and warn people through visual and audio appliances when smoke, fire, carbon monoxide or other emergencies are present. These alarms may be activated automatically from smoke and heat detectors or may also be activated via manual fire alarm activation devices such as manual call points or pull stations. Alarms can be either motorized bells or wall mountable sounders or horns. They can also be speaker strobes which sound an alarm, followed by a voice evacuation.
Fire detectors can detect a range of factors associated with a fire, such as smoke, heat, combustion gas or, ultraviolet and infrared radiation. Even if one of these elements is detected, the fire alarm system will be triggered.