Photoelectric smoke detector and chamber therefor

摘要

A smoke detection chamber for use in a photoelectric smoke detector. The smoke detection chamber comprises a side wall with a double row of generally rectangular vanes arranged to provide a labyrinth extending generally around the entire side wall for ingress and egress of smoke particles, a top and a bottom. A mounting arrangement for a photoemitting diode is provided in the side wall of the smoke detection chamber so that a light beam from a photoemitting diode is transmitted across the smoke detection chamber. The mounting arrangement extends from and is spaced from the bottom to provide minimal interference for entry of smoke particles. The bottom of the smoke detection chamber has an opening therein with a shielding arrangement thereabout open to the chamber for a photodiode detector, the opening and shielding arrangement being located between the centerline of the smoke detection chamber and the mounting arrangement in the side wall of the chamber. The double vane side wall and spacing of the mounting arrangement from the bottom provides the smoke detection chamber with generally uniform smoke penetration properties around its entire periphery.