Round robin comparison of power losses performed by epstein frame and sst above 50 hz at room temperature

Epstein frame and single sheet tester are two methods used for measurement of power losses of the electrical steel sheets or strips. Both methods and the setups are described in the IEC standards. Each national metrology institute or other metrological laboratory has different setups for power losses measurement and the validation of its accuracy and parameters can only be done by comparisons. So far, every performed comparison was carried out only at 50 Hz or 60 Hz. Within the EMPIR project "HEFMAG", improved metrological infrastructure for the determination of power losses using Epstein frame at induction values close to saturation and at frequency ranges between 2 kHz and to 10 kHz was built. To validate the improved setups, a round robin comparison of power loss measurements was conducted by five laboratories. The results of the round robin comparison are discussed including measurement uncertainties.