Michael, it is generally accepted for emissions purposes that if only one sample were tested that it would be the best-case sample. It is also generally accepted that due to site uncertainty and other factors, that if all of the same construction principles and logic were applied to all manufactured items identical to the sample tested that there may be a range of +6dB within all of production.
This is the reason why most EMC consultants like to see a 6dB margin under the limit on a single sample. I have heard that the VDE wants to see either a 6dB margin for a single sample or at least five samples of a product tested to any margin under the limit prior to issuing any CB reports (I don't know for certain, since I have not gone the CB route with the VDE). See Tony Fredriksson's earlier post about samples. Steve Chin StreamLogic Corp. Menlo Park, CA, USA [email protected] The contents of this message in no way intentionally represent the opininions of any being other than myself, be they living, dead, or not of this Earth.
