Abstract:
A quality value for a carbon ceramic brake disc (2) in a vehicle is measured by means of a measuring device (3) installed in the vehicle. The measuring device (3) with a coil (10) is located at a distance (d) from the brake disc (2) in order avoid direct physical contact with the brake disc. The impedance of the coil (10) is measured for at least two frequencies. The resulting measurement values that correlate to impedance values are introduced into a mathematical model in order to eliminate the dependence of the unknown distance (d) and to obtain a quality value dependent on the conductivity of the brake disc (2).