It is suitable for general smoke detection, particularly effective in detecting large visible smoke particles such as those produced by smouldering wood, paper, PVC or polyurethane foam.
The smoke detector detects fire by the scattering of infrared beam, which circuits consist of a set of infrared beam emitter and receiver. The emitting and receiving lens are in the optical sensing chamber, screening any interference from outside lights, without preventing the entrance of smoke particles. In a smokeless condition, it only receives very weak infrared light. When smoke particles enter the chamber, the received light signal will increased due to scattering. When the smoke reaches a predetermined density, it will trigger an alarm signal.
To reduce interference and power consumption, pulsed emitting circuits are used to increase the life of the emitting lens.