drcuthb...@micron.com wrote (in <E6F64B42266D654B80A0F7F4B98212A50F3574@ ntxboimbx03.micron.com>) about 'Average Detection', on Tue, 24 Aug 2004: >One of the earliest posts to this question (I have since deleted that >post) mentioned the incorrectness of averaging after the logarithmic >detector. Averaging after the log detector, I believe, does not >correctly average the signals. However, this appears to be standard and >accepted practice. Even the common technique of averaging multiple >signal measurements in decibels, such as five different PC's, is not >correct. The technically correct method is to convert the measurements >into linear units, average them, then convert to decibels. Any comments >on this?
Well, you are quite right. If the levels in dB are not very different, the error in averaging them rather than the voltages is small, but Of course, if you average 50, 51, 53, 70 and 90 dB you get a silly answer. -- Regards, John Woodgate, OOO - Own Opinions Only. The good news is that nothing is compulsory. The bad news is that everything is prohibited. http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk 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 emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
