Patent ID: 9053620
Filing Date: 2015-06-09
Classification: G08B

Abstract:
1. A fire detector, comprising: an open scattered light detection unit operational on an optical scattered-light principle within a detection space outside of a fire detector housing, said detection unit including an optical receiver sensitive to scattered light within said detection space; an electronic evaluation unit connected to said detection unit and a warning device for outputting an acoustic and/or optical alarm when a fire is detected; an energy storage device for an autarkic supply of electrical power to the fire detector; a voltage measuring unit for measuring a battery voltage present at said energy storage device and a warning device for outputting an acoustic warning if the battery voltage falls below a given voltage threshold; said optical receiver of said open scattered light detection unit also forming an ambient light sensor sensitive to ambient light; and a device for suppressing the output of the acoustic warning if a signal received from said ambient light sensor indicates that the ambient light lies below a predefined brightness threshold.