So, we use a specified margin to the regulatory conducted emission limits.
For sake of discussion let's say 3dB. So during product development we stay at least 3dB below the limits specified in the relevant standard, CISPR 22 or equivalent.
The rationale for doing that is for taking into consideration repeatability of the measurement, tolerances of RFI components (CM inductors, Y capacitors etc) and cover my ass margin to avoid problems with design changes along the way.
But, if the end product is well below the limits, then it's money and project time out of the window
Also, we are the nice one in the bunch, working with safety margins etc. Then we sell the product to a consumer, a kW unit, and that is blown away by a Chinese 10W wall adaptor, with no EMC filter.
So, to the point of the post. What do you guys do? Go to the limit or adopt a safety margin also?
Cheers
Klaus