Surface probe for a road and its use in detecting the condition and the freezing temperature of an aqueous phase prevailing on the surface.

摘要

The sensor comprises two electrodes (14,16) housed in a metallic body (12) in the surface portion of a road body and a Peltier-effect thermo-element (18) associated with one of the electrodes in order to establish a differential thermal condition between the electrodes. The electrodes and the metallic body are connected to a measurement circuit for processing: a first signal representing the resistance between electrodes and metallic body so as to detect a dry or wet / black-ice covered surface condition; or a second differential signal representing the difference between the resistances existing between each of the electrodes and the metallic body so as to detect the freezing temperature of an aqueous phase located on the road by differential refrigeration of the sensor and detection of a change of slope of the curve of variation of the differential signal. The sensor can be used in a detection system forecasting black ice. <IMAGE>