Chris:
In Military testing, an ambient measurement is mandatory, so you are always checking your facility for rogue emissions. Beyond that, you also want to be sure that your measurement analyzer doesn’t have internal spurious signals (we used to call them birdies). In commercial testing, I suppose you could start the day with a simple Peak detector scan. This wouldn’t be much of an overhead, as it would require only a few minutes. That might look very impressive to your auditors when they ask about you diligence and you can show them several hundreds of ambient data files. Practically, even if there are many ambient emissions inside your chamber, what does it matter as long as they are all well below the test limits of the day? I frequently face this condition; not because of true ambient signals getting into my enclosure (my chamber is superbly quiet), but because of signals that leak into the test environment from support equipment needed to exercise the EUT. I have seen software that attempts to delete ambient signals from your operational data, but I don’t like that approach. Ed Price [email protected] <blocked::mailto:[email protected]> WB6WSN NARTE Certified EMC Engineer Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 Military & Avionics EMC Is Our Specialty > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of Chris - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ 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]>
