摘要 |
The optical smoke detector is fitted with an optical bridge (6), which consists of a light source (7), an open measurement path, and an enclosed reference path (7'). A receiver is fitted to both paths, and coupled to these is an evaluation circuit. The optical bridge is also fitted with two circular apertures, affixed in front of the light source. When smoke is present in the measurement path, the light is distorted and the evaluation circuit triggers the alarm. An Independent claim is included for a method of compensating for the temperature drift of the optical bridge. |