Study on measurement uncertainty in immunity testing: IEC61000-4-6

Factors of the measurement uncertainty (MU) are analyzed and calculated, to examine a dominant MU factor in the IEC/EMC immunity standard such as IEC61000-4-3,-6 etc., in accordance with ISO guide 17025 describing uncertainty in measurement. It was assumed that the contribution factors to MU are the measurement system repeatability, accuracy of the signal generator, amplifier gain and harmonics, accuracy of the oscilloscope, mismatch, modulation, and test-setup. From the experimental result, it was obtained that the most important uncertainty factor was ldquotest setuprdquo. This means that ldquosetuprdquo influences the test-level. Therefore, we suggest that if application of the uncertainty is effectively done, it is necessary to define the setup clearly.