Uncertainty analysis of the CISPR/a radiated emission round-robin test results

A large round-robin test (RRT) was carried out to obtain quantitative information about the uncertainties that play a role in an International Electrotechnical Commission/International Special Committee on Radio Interference (IEC/CISPR) radiated emission test in the frequency range 30 to 300 MHz. Two different equipment under tests (EUTs) allowed us to distinguish between the measurement instrumentation and the EUT-induced uncertainties, a subset of the standards compliance uncertainties. This paper presents the rationale behind the various RRT-measurements, the way the ancillary equipment was continuously checked, the measurement results and the results of their statistical analysis. The test sites included open-area test-sites, semi-anechoic rooms and fully anechoic rooms. A major conclusion is that measurement instrumentation uncertainty considerations alone cannot explain the uncertainty relevant in an actual CISPR radiated emission compliance test.