Patent ID: 9013316
Filing Date: 2015-04-21
Classification: G08B

Abstract:
1. A smoke detector comprising: a housing provided with one or more openings for the passage of smoke particles into an interior of the housing; a first electrode and a second electrode disposed in the interior of the housing for generating an electric field by application of an electrical potential therebetween; a detection chamber defined between the first electrode and the second electrode, the detection chamber comprising an ionisation zone for the generation of charged particles by ionisation of air in the vicinity of the second electrode and a drift zone for the movement of charged particles towards the first electrode; a measurement device for measuring an electrical parameter representative of the electrical current generated between the first electrode and the second electrode by the charged particles; wherein the electrical potential between the first electrode and the second electrode is maintained at a first electrical potential level which is less than and in the vicinity of an electrical potential threshold level at which a corona phenomenon is generated such that in the absence of smoke no corona phenomenon is generated in the vicinity of the second electrode and in the presence of smoke the corona phenomenon is generated in the vicinity of the second electrode, and the difference in the measured electrical parameter between absence and presence of smoke is being determined and used to detect smoke.