USER MANUAL
EMDC
–
ENOCEAN MOTION DETECTOR AND LIGHT LEVEL SENSOR
© 2020 EnOcean | www.enocean.com
EMDC User Manual | v1.0 | March 2020 | Page 66/75
10.2
Motion detection
Motion detection works based on the temperature difference between a moving object and
its environment. Detection accuracy can therefore be affected by the following factors:
•
Insufficient temperature difference (leading to no detection)
•
Obstructions between PIR detector and moving person (leading to no detection)
•
Warm moving objects (leading to false detections)
•
Electro-magnetic radiation
For the case of person detection, the temperature of the moving object is the human body
temperature (normally around 36.5 °C / 98 F). If under very hot conditions the temperature
of the environment approaches the temperature of the human body, then detection perfor-
mance will be significantly reduced.
For the same reason, hot objects within the detection area should be avoided. Examples
include standing lights, heaters or electrical equipment generating heat.
To reliably detect motion, an unobstructed line of sight from the sensor to the person(s) in
the detection area is required. Walls, room dividers, plants, book shelfs, hanging lights or
other obstacles within the line of sight can limit the detection performance.
The following factors should be considered to avoid the unintended detection of other warm
moving objects:
•
Rapid temperature changes in the vicinity of the PIR detector, e.g. caused by fans or
fan heaters being switched on or off
•
Lights (especially incandescent or halogen) being switched on or off in the immediate
catchment area
•
Warm moving objects such as animals, machines (e.g. cleaning robots or toys), hot
paper output of fax machines and laser printers, falling flower petals
•
Motion in areas adjacent to the intended detection area, e.g. in the floor or in the aisle
around the detection area or outside of the window
Strong external electro-magnetic fields might induce noise into the highly sensitive PIR de-
tection circuitry and thereby affect the detection performance. EMDC should therefore not be
mounted in close vicinity of electro-magnetic radiation sources such as Wi-Fi access points,
gateways, wireless audio or video systems or other wireless devices.
For consistent detection, the mounting site of EMDC should not be exposed to vibrations or
motion.
