2.2 Sensor
Each sensor includes
The detection range of the passive component and of the active component consists of two "parallel" curtains, which, relative to the walking direction of the passengers, are arranged behind each other (refer to the following scheme).
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Passive component The passive component consists of 6 detector elements the detection range of which is arranged in two curtains being in "parallel to each other".At a wide door , each sensor deploys the signals of 5 detector elements, i.e., the detection range of the two sensors consists of 2 curtains with 5 segments each. |
Active component The active component consists of 4 light scanners the detection range of which is also arranged in two curtains being in "parallel to each other".At a wide door, each sensor deploys the signals of 4 light scanners, i.e., the detection range of the two sensors consists of 2 curtains with 4 segments each. |
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When a person enters the detection range of the sensor, the person is "seen” by the passive component and by the active component. All signals generated in the sensor are amplified and digitized in the sensor and transferred to the analyser via a synchronous serial interface. The analyser uses the signals to determine the counts.
By combining both the passive and the active infrared detection technologies in one sensor the disadvantages of each individual sensor principle can be completely set off by the combination and evaluation of different sensor principles.
The sensors come either with a permanently mounted cable or with a removable cable.
The maximum cable length between the sensor and the analyser is 15m. The number of sensors required for each door depends of the door width; also refer to Section 3.2 Selection of sensors.
