How does a presence detector work?
Principle: (Ultrasonic (US))
Ultrasonic sensors can only be used indoors and detect the smallest movements. The ultrasonic waves fill the whole room and can also detect around objects.
Mode of operation: (Ultrasound (US))
The ultrasonic waves (40 kHz) are actively emitted by the sensor and spread completely in the respective room. They fill the room up to the last angle and enclose objects that are in the room. The sensor detects movement in the room even if there is no visual contact from the sensor to the person. The signal is evaluated according to the Doppler principle. This is why ultrasonic sensors are perfectly suited for open-plan offices and rooms with lightweight construction. And for this very reason, they are particularly recommended for rooms in which sedentary activities are carried out.
Principle: Camera sensor technology
The HPD1 people sensor is the next level of sensor technology. A sensor that accurately detects people and their number. Namely, seated or standing persons even without movement. With this precise detection, faulty switching is avoided. In addition, the shortest follow-up times for light switching are possible. The detection zone of the HPD1 can be precisely limited to an exactly defined area. Thus, for example, a disturbing passage area is completely blanked out. The person sensor can be used for close detection in rooms or for remote detection in corridors up to 15m.
Strong IR LEDs ensure this function even in the dark. They are not visible to the human eye. In outdoor areas, animals often cause faulty switching in conventional motion detectors. This cannot happen with the person sensor, as it only reacts to people. The information is output via a KNX interface or relay. Thus, there are now completely new areas of application in building automation, especially through the information "number of people present".
Functionality: Camera sensor technology
The STEINEL HPD1 is the world's first sensor that can not only clearly detect people in its detection zone but also count them. Even without them moving. The basis for this is provided by a human model created from 120,000 stored images. This is continuously compared and analyzed with the actual images captured (3 per second). In this way, the innovative camera sensor always reports in real time how many people are in a room. Thanks to strong IR LEDs, even in the dark. The image data is of course protected against unauthorized access at all times.