Photoelectric type fire detector and adjustment unit therefor

Abstract

A photoelectric type fire detector is capable of accurately adjusting sensitivity using a scattering and translucent plate and exhibits excellent reliability. The photoelectric type fire detector has a first detection unit and a fourth detection unit for respectively detecting a first received output and a fourth received output from a smoke detection portion realized when the light emitting device emits light and does not emit light in a case where the scattering and translucent plate is not inserted and as well as when no smoke is present, a second detection unit and a third detection unit for respectively detecting a second received output and a third received output from the smoke detection portion realized when the light emitting device emits light and does not emit light in a case where the scattering and translucent plate is inserted and as when well as no smoke is present, and a calculating unit for calculating the physical quantity of smoke with respect to a received output from the smoke detection portion realized when the light emitting device emits light and does not emit light in a state where a fire is supervised based on the first to fourth received outputs and smoke density of the scattering and translucent plate realized when the second and third received output have been obtained.