ADJUSTING METHOD FOR SENSITIVITY OF PHOTOELECTRIC SMOKE DETECTOR

摘要

PURPOSE:To make it easy to regulate the sensitivity of a photoelectric scattering- light system smoke detector by regulating the quantity of emitted light while adjusting a filter provided on the front face of a direct photodetector in the sensitivity regulation system of the photoelectric scattering-light system smoke detector. CONSTITUTION:While filter 4 provided on the front face of direct photodetector 3 that receives direct light from light emission body 1 is adjusted, the quantity of emitted light of light emission body 1 is varied so as to keep constant the quantity of photodetected light of direct photodetector 3, thereby attaining sensitivity regulation. Therefore, scattering-light photodetector 2 that photodetects scattering light due to smoke is not unneeded for the sensitivity regulation, so that the sensitivity regulation can easily be carried out.