Prescribes methods of measurement of insertion loss of passive radiofrequency suppression filters, which may consist of singleelements, such as capacitors, inductors or resistors, orcombinations of inductors, capacitors and resistors of either thelumped or distributed types. The methods include those for use in alaboratory or on a production line, utilizing fixed impedanceterminations or "worst case" terminations, those to be used in situor in model installations, and provides for voltage and currentloading.