Rain sensor/light sensor, function - GF54.21-P-4123-04R
Principle of operation of rain sensor
Infrared light is radiated by the infrared transmitter unit (1) and led to the windshield (3). The intensity of the light reflected at the windshield (3) is measured by the infrared receiver unit (2).
If the windshield (3) is dry in the area of the rain/light sensor (picture A), then the light is almost completely reflected and the infrared receiver unit (2) measures a high light intensity.
If the windshield (3) is wet in the area of the rain/light sensor (picture B), then part of the light is scattered from the glass of the windshield (3). As a result the intensity of the reflected light reduces and the infrared receiver unit (2) measures a lower light intensity.
The light intensity measured by the infrared receiver unit (2) represents a measure for the degree of wetting of the windshield (3). The lower the measured light intensity the higher the degree of wetting of the windshield (3).
Principle of operation of the light sensor
The light sensor measures the light intensity falling on it from outside.
The information is transmitted on the Controller Area Network bus class B (interior) (CAN-B) via the overhead control panel control unit.