Abstract. We present a method for the evaluation of measurement uncertainty in radiated EMC tests. It is based on the measurement of surface current densities on a sphere, the results are compared to the surface current distribution on a sphere in a free-space environment obtained by numerical calculations. The free-space is considered to be a reference field generator. By this method we avoid burdening any systematic deviations of one particular (historic) method to any of the others. We evaluate the ratio J/E of the measured surface current density J and the measured empty electrical field strength E for both the reverberation chamber and the semi-anechoic chamber.