Smoke detector types and application
Point type smoke fire detector
As shown in the figure below, the infrared light emitted by the detector’s light emitting component would not enter the light receiving component under normal conditions.When smoke enters the detector, infrared light scattered by smoke particles enters the light receiving component.The resistance of the optical device is equal to the intensity of the infrared light received. The smoke concentration increases, the scattered infrared light increases, and the resistance of the optical device decreases. When the smoke concentration reaches the set value, a fire alarm signal is sent.
Point-type smoke detector can basically meet the general requirements of indoor fire detection. It is the mostly used fire detector.
The following places are suitable for installing point-type fire smoke detectors.
1.Restaurants, hotels, teaching buildings, office halls, bedrooms, offices, shopping malls, train carriages, etc.
2. Computer room, communication room, movie or TV projection room, etc.
3. Stairs, walkways, elevator engine room, garage, etc.
4. Library, archives, etc.
Linear beam smoke detector
Linear beam smoke detector usually refers to linear infrared beam smoke detector. As the fire smoke rises, the beam is blocked and the signal to the receiver weakens.When the dimming rate reaches the preset value, the detector will send out a fire alarm signal.
Both point-type smoke detector and line-beam smoke detector give an alarm when visible smoke diffuses to the detector and reaches a certain concentration. These two kinds of fire detectors are suitable for fire detection after the occurrence of fire and develop to the visible smoke stage.
Suction smoke detector
Aspirated smoke detector actively sucks air or smoke samples and sends them to the detection chamber with very high sensitivity for analysis.It can detect minute changes of smoke concentration on site, and send alarm signal in the stage of heat or smoulder, which can detect fire early and prevent it.
Aspirated smoke detector is suitable for early fire detection in smoldering stage. The following places are suitable for installation and use of aspirated smoke fire detectors.
1. Places with high-speed airflow.
2. Large space, above the stage, building height over 12m or places with special requirements, not suitable for point-type smoke and temperature fire detector.
3. Low temperature place.
4. Places where covert detection is required.
5. Important sites requiring early fire detection.
6. Places unsuitable for people to enter.