Within the scope of different projects on electrical machines and power electronics it is often necessary to measure temperature as accurate as possible. To meet these requirements various types of probes (thermocouples, thermistors, platinum resistance thermometer) are used. Temperature differences measured often come to only a few degrees Celsius, while the operating temperature at which these differences are measured varies over a larger scale. Therefore the tolerances specified by the producers of temperature sensors are often insufficient, and a calibration of the sensors is necessary. The testing of the temperature probes should take place under similar mounting conditions. The calibration should be at least as precise as a platinum resistance thermometer of tolerance class 1/3B calibrated at a temperature of 110°C. The proposed calibration unit allows a calibration of the Pt1000 thinfilm elements under realistic mounting condition up to about ±0.15K. not assigned KP: Partner aus der Industrie (anonym)