AO-ST-P-DA Smoke Detector for Ceiling Mounting

The optical detector gives an early warning of a starting fire, especially from fires producing big particles i.e. smoldering fires. The detecting chamber contains an emitter and a receiver. Normallly the pulsed light-ray from the emitter does not reach the receiver. When smoke particles enter the chamber they will reflect the light-ray onto the receiver and alarm is obtained. The alarm is indicated by a red LED on the detector, and the alarm status continous until manual reset is made on the control unit. In operating position, the emitter is pulsing every 8 second to maintain a low monitoring current. The detector design provides strong immunity to air velocities, contamination and RF interference. The detector module fits into the base by means of the bayonet principle, enabling easy mountage of the detector. If the detector is contaminated, it will gradually go into an alarm position. In order to avoid nuisance alarms, the detector is provided with a pre-alarm or service alarm (green LED) showing that the detector module should be cleaned.