A LIGHT-SCATTERING-TYPE SMOKE DETECTOR

摘要

A light-scattering-type smoke detector is disclosed which comprises a base portion to be secured to a ceiling, a head part forming one of the parts of a detecting portion to be detachably mounted to the base portion through setscrews passed therethrough, and a dark box forming the other of the portions of the detecting part to be detachably connected to the head part by screwing the setscrews thereto, the dark box comprising a body portion and a cover portion put one upon another. The body portion has a printed circuit board integrally secured thereto on its upper surface and the dark box is surronded by a labyrinth around its outer periphery that is internally provided with a light projection element and a light receiving element. The smoke detector allows the dismounting of the head part from the base portion, and the dark box from the head part so that maintenance and repair of the smoke detector can be carried out quite easily.