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  Updated: 13 Nov 2018


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Projecting Guide

An occupancy detector or presence detector is markedly different from a motion detector.
An occupancy detector is much more sensitive and can detect the presence of people not even moving.

An occupancy detector has a so-called Fresnel lens of high resolution optics, higher gain and thus increasing sensitivity.

The requirements for detecting presence is higher than those for motion.

Occupancy detectors and motion detectors are both IR detectors (infrared radiation). The construction of these  detectors is such that it is not just enough with a radiation source for detection.

The working principle requires both a radiation source of a certain size, and that this source moves through the detector's sensing field.

The best detection is obtained when the radiation source  passes at 90 degrees to the detection fields.

A human being transmits at rest 50-100W, a rather powerful radiation source and the detector records this in a pyroelectric radiator.

Occupancy detector - room
A technique to detect the presence of people and control the lighting/ventilation/air conditioning in order to save energy.

Detects extremely small movements:

  • human being at sleep

  • human being sitting absolutely still

  • permanent presence of humans beings

To detect a human being at sleep or human being sitting still at his/her desk making extremely small movements, it is essential that you use an occupancy detector.

The detector can include a timing circuit (or programmed in the controller) that accumulates the latest movements and automatically extends the time in the output relay.

This period must be as short as possible.

An occupancy detector must function in a classroom, a conference room and office as well as registrating a sleeping person in a room where even ventilation and air conditioning is controlled by the detector. The occupancy detector detects the constant presence of people.

An occupancy detector/motion detector should not be used to turn on the lights in rooms where there is daylight.

Anyone who enters the room shall be compelled to turn on the light, if need be, and then to a level sufficient for the operation. See light control.

Motion Detector
Today's motion detectors for lighting/ventilation turns on and  off and stops wirelessly and automatically.

AP's motion detectors are the ideal solution for any room in which it is important to have functional lighting/ventilation such as:

  • corridors

  • staircases

  • bathroom

  • toilets

  • kitchens

  • cellars

  • laundry spaces

  • and all areas where lighting/ventilation is required only for a short time

Motion detectors provide safety, convenience and energy savings as well as automatic lighting control.

Närvarodetektor, rum - IDW


Rörelsedetektor, utomhus - ODD


Rörelsedetektor infälld, rum - IDS


Rörelsedetektor, rum - IDR


Närvarodetektor - TOD


Proper mounting location is critical for proper functioning of the occupancy detector.
The operating area of persons in a room should mainly be in monitored area.

  • A person must occupy the monitored area.

  • The occupancy detector requires a clear view of the people present

  • The occupancy detector does not detect through glass. (Glass doors and windows limit the monitored area.)

  • Shadowing by moving walls, shelf walls, plants, etc. should be avoided.

In principle there are no limits to the monitored area. With increasing distance to the detector, however, the sensitivity decreases.

Possible sources of error

  • Moving objects (curtains over radiators, swing doors, etc.) within the area monitored by the detector

  • Rapidly heated objects (lamps, air intakes, radiators, etc.)

  • Direct solar radiation on the detector

Installations hints

Place the detector so that it is not exposed to direct sunlight or directly above strongly exothermic sources.

Avoid items that can block coverage (large pieces of furniture, curtains, etc.).

Do not install where the detector is exposed to direct sunlight or directly above strong sources of heat.


Make sure the detection area does not have any obstructions (plants, large pieces of furniture, curtains etc.) which may block the detection.



Occupancy detectors utilize infrared measurement techniques to confirm the presence status on the premises.

The infrared energy emitted from the human body can not pass through solid materials such as walls, partitions, glass, wood, curtains, metals, etc..

Make sure the detection zone contains none of the above obstacles.

Reflective materials (mirrors, thin metal sheets, marble, tiles, etc.) can reflect the infrared radiation.

The detection coverage can be increased if the wall / floor contains the above mentioned materials.

The infrared detector is more sensitive to  movements "through" the detection zone than "against" or "off" the detector.

When selecting a location, ensure that the detector can "see" the movement through the zone and that the object does not come towards the detector.

Several occupancy detectors can be used to detect the presence status in areas that a single detector can not detect.

Occupancy detector, ceiling - IDC


Motion Detector, Ceiling - ICD

E-mail: ewert@automatikprodukter.se     

Phone: +46(0)31-287202

Mobile: +46(0)708885298



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