Brake discs are subject to the highest loads in use and are responsible for the safety of vehicles. For this reason alone, brake discs are thoroughly inspected on test benches. Brake discs are checked for various characteristics at a speed of approx. 2000 rpm on special testers. Capacitive sensors are used for checking the geometric characteristics such as concentricity, thickness and wear. As the deformations only occur in the range of hundredths of micrometres, only very precise sensors can be considered for this. The thermoMETER infrared sensors are used for examining the thermal characteristics of the brake disc. The absolute temperature can be monitored with these so that the thermal drift over a long period can be established.