Uncertainty considerations in compliance-testing for electromagnetic interference

Product assurance aims at manufacturing and marketing products that meet the requirements of the customer and the regulatory authorities, thus meeting the requirements of society at large. This involves manufacturing, testing and certification of the product. Thus the product assurance actually involves the manufacturers, testing laboratories, certification bodies directly and standardisation bodies, regulatory authorities indirectly. The compliance or otherwise of a product to its technical specification is judged based on compliance criteria: the regulatory requirements refer to technical specifications. The product characteristics vary due to inherent variability in the manufacturing process. The evaluation of the product characteristics in the manufacturing organisation or testing laboratories involves measurements and there is an uncertainty factor associated with measurement results. The compliance decision has to take the uncertainty factors into consideration. The paper describes how these factors have been considered for judging compliance for electromagnetic interference/electromagnetic compatibility (EMI/EMC) and safety.