Glossary A–ZLetter P
Presence detector
A presence detector is a sensor that detects whether people are in an area and then triggers a signal.
It usually works with heat radiation (infrared), radar or ultrasound and does not capture an image. It is known from lighting control in corridors and offices.
At screens, a presence detector can wake the display when someone enters the room and send it back to standby after a period without movement. It can also trigger content, such as a greeting at the entrance or a notice at the shelf. In meeting rooms it reports whether a room is actually occupied.
Operators should bear in mind that a presence detector only recognises presence, not who or how many people are there. It is no substitute for counting or audience detection. Sensitivity, detection area and hold time must suit the location, otherwise the screen keeps switching on and off. Whether personal data arise in a given case depends on the technology and evaluation and should be checked.