Jim As others have suggested, I'd recommend leaving you chamber as it is, HOWEVER, I would perform correlation to OATS using some of your typical EUT, as well as a CNE or other noisy "box" - I've seen >10dB difference, relative to limit, between 3m FAC's and 10m OATS measurement when measuring an EUT that had a cable that dropped down to ground plane.
Regards Charlie From: Jim Hulbert [mailto:[email protected]] Sent: 16 December 2011 21:49 To: [email protected] Subject: [PSES] Semi-Anechoic Chamber Question I have an older 3-meter semi-anechoic chamber that is fully compliant for radiated immunity testing per IEC 61000-4-3. Occasionally I also use the chamber to run a radiated emissions "pre-scan". When I use the chamber for the pre-scan up to 1 GHz, I remove the foam absorbers and ferrite floor tiles between the antenna and EUT to get a reflecting ground plane. The aborbers are no problem but the floor tiles are quite heavy. As an easier option, I'm thinking of coming up with a relatively light weight conductive surface that can be easily placed over the floor tiles and easily removed again. Something like a foil that could be rolled into place and then rolled up again when done. I could connect the foil to the shielded room floor to ground it. Does anyone have any experience doing something like this or would I be wasting my time and better off continuing my practice of removing the tiles? I'm not looking for compliance emissions measurements because I'm limited to 3 meter distance and an antenna sweep height of 3 meters. However, I would like to get the best pre-scan data I can to minimize surprises when I do go out to an open area test site for the final test. Thanks. Jim Hulbert - ---------------------------------------------------------------- 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]<mailto:[email protected]>> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. 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]<mailto:[email protected]>> Mike Cantwell <[email protected]<mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected]<mailto:[email protected]>> David Heald <[email protected]<mailto:[email protected]>> - ---------------------------------------------------------------- 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://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. 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]>
