The optical smoke detector reacts to visible smoke particles. If too much smoke gets into its measuring chamber, an alarm is triggered. Inside the measuring chamber, an integrated infrared light source generates a light pulse every 8 seconds. Only when smoke particles get into the measuring chamber during a fire do the light fall on the photodiode. A relay switches and the alarm control panel reports a fire alarm. The optical smoke detector is mounted on the ceiling in the middle of the room. The minimum distance to the side wall is 30cm. We recommend one smoke detector per hallway, staircase, living room and bedroom. By adjusting a jumper, you can configure the optical smoke detector as a NO or NC detector. This means it fits any wired alarm system. The smoke detector is supplied externally with 12V operating voltage and is EN54 certified.