A detailed analysis of EMI test receiver measurement uncertainty

The paper describes how the total uncertainty of an EMI test receiver can be determined from a standardized calibration report. In addition to the three main parameters: absolute level and frequency response, linearity of the detectors and the uncertainty of the step attenuators, many further parameters including the uncertainties of the calibration laboratory's calibration system are contributing to the total uncertainty. Among these parameters are data on temperature stability obtained from the design engineer, as well as data on internal gain drift between internal gain adjustments obtained from observation. Generally a differentiation has to be made between uncertainty arising from imperfect correction for systematic effects and uncertainty arising from random effects.