Capacitive sensor for measuring moisture content on vehicle screen

摘要

The screen wiper (4) as the first capacitor electrode swivels over the working range of the second capacitor electrode (2) at least leading to the leaving of a determined amount of moisture at least over time. During this proximity, the capacitance effective between the two capacitor electrodes (1, 2) increases and the size of this capacitance determines the amount of moisture. An electronic evaluation unit is provided. The second capacitor electrode is arranged at the vehicle screen e.g. windscreen (6) inside the vehicle passenger space (8). The second capacitor electrode is embedded in the glass of the vehicle screen. At least one auxiliary electrode (3) can be arranged in the working region (11) of the second capacitor electrode and this e.g. ring shaped can encircle the second capacitor electrode.