Hi, In the interest of not divulging proprietary info, I will not specify the companies involved although I can say that I have never worked for either the manufacturer or the test lab.
But I have seen a final report from a very reputable lab and written for a very reputable company that only had 0.7dB of margin under the legal limit. The emission was generated by the EUT. Furthermore, the report was a formal FCC Class B Grant Certification submittal and the FCC issued the Grant. I have worked at companies that imposed an internal requirement of as little as 3dB below the limit on a one off sample. The final decision on margin required is usually a blend of business and technical factors, each case being different. Regards, Tony Fredriksson NET Scott Douglas wrote: > Hello all, > > When doing EMI scans of ITE, I have always worked with a margin of 2 dB > less than the actual limit. No test house I have ever been to will give a > "meets the requirements..." without having this margin. Can anyone point > out if this is an actual requirement built into any of the standards, i.e. > EN 55022 or FCC Part 15, etc. and if so, where is it in writing? > > I understand about measurement errors, product to product differences and > repeatability of testing issues. Just want to know if the 2dB margin is > actually written into law. > > Thanks for your comments. > Scott > [email protected] > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to [email protected] > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to [email protected], > [email protected], [email protected], or > [email protected] (the list administrators). --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
