Obscuration smoke detector and use thereof

摘要

The device has an optical bridge with a light source, measurement and reference paths, each with a receiver, an evaluation circuit and a second light source. An externally open measurement path leads from each light source to one receiver and an externally screened reference path leads from each light source to the other receiver. Each receiver acts as measurement receiver for one source and a reference receiver for the other and vice-versa. The device has an optical bridge with a light source (L1), measurement (M1) and reference (R1) paths, each with a receiver (E1,2), and an evaluation circuit (3). A second light source (L2) is provided. An externally open measurement path leads from each light source to one receiver and an externally screened reference path leads from each light source to the other receiver. Each receiver acts as measurement receiver for one source and a reference receiver for the other and vice-versa.