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Presence and Motion detectors


Both device types have a sensor system for motion detection and a light sensor system for brightness measurement. Nevertheless, presence detectors and motion detectors are each suitable for different applications.


Motion detectors detect larger movements within their detection range, for example when a person is walking forward or gestures in a disorderly manner. As soon as motion detectors detect a movement, they measure the brightness once with their light sensor technology. If this is below the previously set brightness value, they activate the lighting. If they no longer detect any movement, they switch off the light again at the end of the follow-up time.


Motion detectors, with their simpler motion sensor technology and unique light measurement, are ideally suited for passageways, sanitary areas and side rooms with little daylight or short-term use, as well as for outdoor applications.


Presence detectors also detect larger movements, but within their presence range they also register fine motoric and even the smallest movements such as typing on a PC keyboard. Unlike motion detectors, presence detectors can therefore detect the permanent presence of people - for example at a desk in the office.

If movement is detected and brightness is insufficient, presence detectors activate the lighting. Unlike motion detectors, however, they do not measure light just once but repeat the measurement as long as they detect presence. If the required illuminance is already achieved by daylight or ambient light, presence detectors switch off the artificial light in an energy-saving manner even if there is a human presence. Alternatively, they deactivate the lighting at the end of the switch-off delay time.

Presence detectors with constant-light control provide even greater convenience and energy efficiency when people are present. Because based on their continuous light measurement, they can continuously adjust the illuminance of the artificial light to the natural lighting conditions by dimming.


Presence detectors are ideally suited for indoor areas where people are permanently present, especially in areas with daylight, due to their more precise motion detection and continuous light measurement. They are therefore preferred for use in offices, classrooms or recreation rooms, for example.