The ceiling motion sensor KINASGARD® DBWF detects the presence of persons and movements and has a switching contact as an output (changeover contact). The motion detector is used for monitoring and detecting statuses and for motion-dependent control of room functions, e.g. for lowering the temperature of unused rooms. The ceiling motion sensor is used for installation in suspended ceilings in corridors, offices, as well as in residential and business facilities. The measuring transducer is accommodated in a separate enclosure. The sensor detects motions over an aperture angle of 110° and a perimeter of 360°. The patented lens system with 20 individual lenses results in only very small dark areas that are only a few centimetres wide even at a distance of 10 m, thereby reliably detecting small movements.