Photoelectric Smoke Detector

Photoelectric Smoke Detector

A photoelectric smoke detector is a type of smoke detector and alarm initiating device using the scatted light principle and is designed to detect the presence of smoke from fire.

A photoelectric smoke detector comprises an enclosure comprising the following components;

  • a fine mesh shield to prevent the ingress of large particles and insects but still allows the ingress of smoke;
  • a labyrinth vanes extending generally around the entire side wall of the smoke detection chamber to enable the ingress and egress of smoke particles;
  • a light source for emitting light energy;
  • a light receiver for providing an output signal at a signal magnitude proportional to the intensity of the light received;
  • an electronic circuit that receives the output signal and transmits that signal to the fire detection control and indicating equipment ("FDCIE").

A photoelectric smoke detector operates on the principle that, under normal circumstances in clean air a light wave will travel in a linear direction (straight line) indefinitely. A photoelectric smoke detector leverages the concept that light can be scattered (reflected and refracted) when a light wave is contaminated by the airborne solids suspended in air (smoke).

In this scenario, the light source beam is scattered by the smoke within the chamber of the smoke detector where the light waves that are reflected and refracted are received by the light source receiver.

Disclaimer

In preparing this definition, we have drawn from various sources including Legislation, Codes, Standards and industry information, research and knowledge.  Like the english language, these definitions may subtly change from time to time. As such these definitions are provided solely on the basis that users will be responsible for making their own assessment of the definition and and are advised to verify all relevant representations, statements and information.