FD6130L Optical-smoke detector provides early warning of open or concealed fire, responding to smoke emissions concentration. Infrared light emitter and receiver are mounted in fire detector’s optical chamber. The principle of functioning in based upon smoke particles entering the detector head’s smoke chamber causing distraction of infrared rays within the chamber (the Tindal effect). The light is transformed into voltage. The activation threshold of the detector is factory set at a specific smoke concentration level. FD6130L complies with the European Standard EN54-7 and is effectually protected against, high humidity and strong air flow.