LIGHT SCATTERING SMOKE DETECTOR

摘要

Disclosed is a light scattering smoke detector with a novel structure for preventing direct irradiation of a light sensing element with reflected light from the inner walls of its detection chamber. The detector comprises a detection chamber composed of a cylindrical side wall closed by opposite end walls. A light source and light detector are located in the chamber so that the sensing element is not irradiated directly but is irradiated by light reflected from smoke particles. The side wall consists of plurality of similar laminae arranged circularly and shaped to form a serpentine path between adjoining laminae. Smoke particles can freely enter the chamber via the serpentine path and light from the light source is effectively reflected out of the side wall but not to the light sensing element.