Hi Tim -
I would say you need to measure it. Referencing EN 55022:2006 section 6.1 Limits below 1GHz: If the reading on the measuring receiver shows fluctuations close to the limit, the reading shall be observed for at least 15 s at each measurement frequency; the highest reading shall be recorded, with the exception of any brief isolated high reading, which shall be ignored. I interpret "brief and isolated" to imply the high level is only present once during the 15s observation period for no more than one measurement (measurement period being 1 second I think for QP measurements). When you say peak in your email, do you mean "highest level" or actual peak (versus Quasi-Peak) reading ? I have seen similar issues with an external USB drive (signal level jumping up and down) but have, so far, been lucky with the QP reading being below the limit , well below the peak reading and more stable than the peak measurement. Good luck, Mark Mark Briggs [email protected] Sent by: [email protected] 02/28/2007 04:54 PM To [email protected] cc Subject Radiated Emission Question Hello, I have a question regarding radiated emission testing where a peak is not constant. The peak in this case comes in for about 5-6 seconds, then off for a few seconds and back in again. This is a peak generated by the EUT, which is an ITE device. The question is, should the lab take the maximum peak, or just skip the reading because it is random. I have verified it is from my equipment. The problem is this particular reading is failing. I have been told by some that the reading needs to be taken and some say that reading should be omitted from my test data. I welcome any suggestions on how to handle this. I do not want to spend unnecessary time debugging if I don’t need to. Please reference any particular paragraphs in the ANSI or CISPR standards to back up the answer, because I will need to justify this to the engineering team. Thanks, Tim Pierce _____ AOL now offers free email to everyone. Find out more about what's free from AOL at <http://pr.atwola.com/promoclk/1615326657x4311227241x4298082137/aol?redir=http%3A%2F%2Fwww%2Eaol%2Ecom> AOL.com. This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
