Usually you do pre-tests before doing the expensive ones. Recently on HN was a link to https://www.nutsvolts.com/magazine/article/low-cost-emi-pre-compliance-t

Usually you do pre-tests before doing the expensive ones. Recently on HN was a link to https://www.nutsvolts.com/magazine/article/low-cost-emi-pre-compliance-testing https://www.nutsvolts.com/magazine/article/low-cost-emi-pre-... that allows you to do your own pre-tests. Also there are companies to do these pre-test measurements as a service which has the same result but is _way_ cheaper than a "certification" test.