| 摘要 |
The invention relates to a device for detecting snow and ice which has a sensor arrangement (11) comprising a humidity sensor (13) and an ambient temperature sensor (12). An evaluator switch is controlled according to a humidity sensor- measured variable, producing a control signal at set humidity values for defrosting a surface which is being monitored for snow and ice. The ambient temperature sensor (12) activates the humidity sensor (13) within a temperature range of between +2 .degree.C and -12 .degree.C. The humidity sensor (13) itself has a PTC heating element, the current consumption of said heating element being used as a measure of humidity. Both the ambient temperature sensor (12) and the humidity sensor (13) are positioned at a mutual distance in a longitudinally extended sensor cartridge (14) made of plastic. The temperature sensor (12) is thermally decoupled from the PTC heating element. The PTC heating element is built into a metal sleeve in such a way that it is corrosion and humidity proof.
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