On the Risk to Declare EMC Compliant a Faulty EUT During Radiated Susceptibility Tests in Reverberation Chambers

This paper presents a general method, experimentally validated, highlighting the influence of the number of stirring configurations used during radiated susceptibility tests performed in reverberation chambers in terms of reliability and confidence of the obtained results. This Monte-Carlo based approach (with routines available on demand) computes the risk to declare compliant from an electromagnetic compatibility (EMC) point of view a faulty equipment under test. This risk is calculated according to the number of stirring configurations chosen for the test and to the uncertainty of the electromagnetic field strength applied on the equipment. The proposed method is shown to be applicable for any equipment independently of its size and directivity (or more precisely its receiving polarization pattern). Overtesting is shown in this context to be a promising solution able to increase the confidence of the users about the EMC compliance of tested equipment. The paper also illustrates the possibility to extract the minimum susceptibility level of a valid EUT as a function of the testing conditions.