Reducing the standard compliance uncertainty by using ferrite type CMADs during radiated disturbance measurements acc. to CISPR 16-2-3

The consideration of measurement instrumentation uncertainty (MIU) is common practice when determining compliance or non-compliance with a disturbance limit. But MIU is just a subpart of the standard compliance uncertainty (SCU) which also addresses uncertainties related to the EUT set-up, EUT operation and measurement procedure. One major influence quantity of SCU is the termination of cables leaving the test volume of the radiated disturbance measurement set-up. With the publication of Amendment A2 to 3
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Edition of CISPR 16-2-3 in 2014 new requirements for minimizing this effect become effective. It requires the termination of cables leaving the test volume using a ferrite type common mode absorption device (CMAD). The significant technical changes and measurement results with and without using CMAD are presented.