PHOTODETECTOR WITH COATED REFLECTOR

摘要

A corrosion resistant photoelectric smoke detector incorporates a housing with a plurality of smoke admitting openings. The housing defines an internal smoke receiving region. A source which generates a beam of radiant energy which is projected across the region is carried by the housing. A collector of radiant energy is positioned along the axis of the beam. The collector is coupled to a sensor of radiant energy. Radiant energy in the beam scattered by smoke in the internal region is in part incident on the collector. The collector, via a plurality of reflections directs the incident scattered rad iant energy onto the sensor. The collector carries a corrosion resistant coating or i s formed of a reflective corrosion resistant material.