An optical smoke detector or photo-electric alarm works on the light scattering principle. The sensor chamber checks for smoke particles after every 10 seconds with the help of a pulsed infrared LED beam. These smoke detectors indicate a fire in non-smoking zones. They are used widely by commercial and industrial buildings as a safety measure. A commercial smoke detector sends a signal to the fire control panel while household fire alarms give audible or visual alarm from the detector. Smoke detectors are disc-shaped set up in plastic enclosures. The process of smoke detection takes place either through ionization or the photoelectric process. The detectors can use either of the two sensing methods. Domestic smoke detectors are interlinked and if one of them detects smoke, all the alarms trigger altogether even if the household power has gone out. Smoke detectors are used mostly in hospitals, gyms, office buildings, industries, malls and commercial buildings. How do Optical Smoke Detectors work? Smoke detectors work by detecting smoke in the first few seconds of the incident and send the signal to the fire control alarm panel. The types of detectors vary depending on the indicated fire that they detect. It also depends on the detection principle. Smoke, heat and flame are three main indicators of fire. The process used for detecting smoke is based on the light- scattering principle. When there is fire, smoke particles enter the optical chamber of smoke detectors. The LED light refracts and scatters on a photodiode. Then, the optical smoke detector sends the fire alarm signal to the control panel.

The Conventional heat detector uses a state of-the-art optical sensing chamber. This detector is designed to provide open area protection and to be used with most conventional fire alarm panel. The Conventional rate of rise heat detector uses thermal component to detect the temperature changing in the environment. It can enable fire alarm when the temperaturedifference achieved the setting rate of rise temperature valuereach the setting fixed value. It has a stable and reliable workingperformance. Two LEDs on each detector provide local 360 visible alarm Indication. They flash every six seconds indicating that power Is applied and the detector is working properly. The LEDs latch On in alarm. LEDs will be off when a trouble condition exists that the detector sensitivity is outside the listed limit. The alarm can be reset only by a momentary power interruption. The detector that initiated the alarm condition will have its red LED and relays latched until reset by panel.