SMOKE DETECTOR USING SCATTER EMITTER AND OBSCURATION EMITTERAND A SINGLE RECEIVER

摘要

A smoke detector (50) includes a housing defining a dark chamber (24) admitting test atmosphere. A light receiver is disposed within the chamber. A scatter emitter (32) is positioned within the chamber such that light strike s the receiver (28) when reflected off particles suspended in the test atmosphere. An obscuration emitter (38) is positioned within the chamber suc h that light emitted is directed to the receiver (28) unless obstructed by particles suspended in the test atmosphere.