Performance Evaluation Criteria for Quantitative EMC Proficiency Testing: Empirical Bayesian-Based Versus Normality-Based

In this study, two actual quantitative Electromagnetic Compatibility (EMC) Proficiency Testing (PT) cases (both in the economically and regulatorily significant RF frequency range 1-18 GHz) are documented. These cases clearly demonstrate the unsuitability of the ISO 13528 Normality Criteria as a Performance Evaluation Tool for EMC PT. In the first case, we had a high competency rate (> 90%) among participants, but the misapplication of the Normality Criteria resulted in the arbitrarily and incorrectly placement of a substantial number (~38%) of the participants in the “Warning” or “Fail” Zones. In the second case, we had a high incompetency rate (~ 50%) among the participants, the misapplication of the Normality Criteria resulted in the exact opposite result (i.e., it only found about a 10% incompetency rate among participants). To cure such serious misclassification issues resulting from the misapplication of the Normality-based Criteria, an Empirical Bayesian-based Criteria (that incorporates the use of the regulatorily-prescribed Maximum Permissible Error, Up, as the a-priori information) is proposed and demonstrated to be a superior alternative.