Passive infrared measurement
Most current occupancy/motion detectors use infrared light as their measurement method. This light is emitted by living beings and all warm objects (e.g. cars with a warm engine). The system measures the temperature differences in its detection area that occur when a warm object moves. The sensor in the occupancy/motion detector itself does not emit any signals, hence its description as “passive” (PIR = passive infrared sensor). A sensor’s detection area depends on the optical system, but also on the number of installed PIR sensors.
As well as PIR sensors, the detectors have brightness sensors. When movement is detected, occupancy/motion detectors switch on the light if the level is below the brightness threshold set.
More than just on/off switching
The supreme advantage of an occupancy detector is mixed light regulation. Here, the detector evaluates the natural light that is falling: it not only switches the artificial light on and off, but also dims it according to natural light levels, so that the individually set value for the room’s desired light level is reached. Therefore only a percentage of the energy is required, whereas previously there was only a choice between 100% (on) and 0% (off). Light regulation is possible with our DALI, 1-10V and KNX devices.
Discover examples of use here!
