Ultrasonic motion detector
The ultrasonic motion detector is an existing from an ultrasound transmitter and receiver motion detector responsive to a change (set-actual comparison) of the emitted by the detector and received as a reflection ultrasonic waves ( ultrasound ) is responsive in the monitoring area ( Doppler effect ) , e.g. B. on a person (or animal) located in this area, and indicates this by interrupting the reporting line (active detector).
The monitored volume has an "egg-shaped" shape. The carrier medium for the sound waves is air. For this reason, ultrasonic motion detectors must not be installed behind curtains, above radiators, in the area of ventilation inlets or outlets, in the vicinity of strong sound sources or in the area of loosely suspended objects (e.g. lamps).