Smoke And Heat Detectors

Smoke Detector










Smoke detectors are essential because they provide an early warning of a fire and therefore occupants can evacuate the building immediately because of the early warning.

Smoke detectors detect most fires much more rapidly than heat detectors. They automatically detect a fire by sensing smoke particles. The smoke particles may be visible or invisible to the human eye.

Common Smoke Detectors


Most smoke detectors work either by optical detection (photoelectric) or by physical process (ionization) .

Anatomy of a typical smoke detector





Ionization detectors

Analyze particles in the air. When the it senses abnormal conditions, the system actives the alarm.




Photoelectric detectors

Uses light sensors to detect the presence of smoke



Heat Detector


Heat detectors are available in two general types: rate-of-rise and fixed temperature.





Rate-of-rise heat detectors activate the alarm when the room temperature increases at a rapid rate.





Fixed-temperature heat detectors activate the alarm when the detector components melts at a set temperature. Some need to be replaced after they have activated an alarm.