David, In my experience, I've found that nearly all test houses accept the interpolated results. That said, the 3-meter measurement is understood to have near field issues at frequencies on the low end. Also, the 3-meter test needs to be performed in a chamber which has been tested for a uniform field over the frequency range in question. Otherwise, the best you can hope for is results considered only for pre-compliance and a final test in a fully qualified chamber is needed. In any case, you will need to factor in uncertainties and allow for a minimum passing margin, typically from 3 to 6 dBuV.
Best of luck, Doug ------------------------------------------------------------------- *I'm here to help you succeed! Feel free to contact me with any questions related to product safety, certifications, risk assessment, or EMI ... at no obligation. I'm always happy to help!* Douglas E Powell *Vertex Compliance Consulting* Laporte, Colorado USA 970-646-3732 doug...@ieee.org <doug...@gmail.com>doug...@gmail.com <doug...@gmail.com> http://www.linkedin.com/in/dougp01 On Mon, Oct 28, 2019 at 2:48 PM Grasso, Charles <charles.gra...@dish.com> wrote: > Take the reading. It’s the only way to be sure.. > > > > It is not unusual for a product to pass @ 3m and then fail at 10m (or vice > versa). > > > > Thanks! > > > > Charles Grasso > > W: 303-706-5467 > > > > *From:* John Woodgate [mailto:j...@woodjohn.uk] > *Sent:* Monday, October 28, 2019 1:30 AM > *To:* EMC-PSTC@LISTSERV.IEEE.ORG > *Subject:* Re: [PSES] Reading or Limit Conversion? > > > > This message originated outside of DISH and was sent by: > owner-emc-p...@listserv.ieee.org > > This inconsistency (in the underlying CISPR standards) should be addressed > by CISPR, but it is difficult to get consensus whenever it is discussed. > > Best wishes > > John Woodgate OOO-Own Opinions Only > > J M Woodgate and Associates www.woodjohn.uk > > Rayleigh, Essex UK > > On 2019-10-28 07:05, Charlie Blackham wrote: > > David > > > > Hmm, different standards appear to deal with this differently: > > - EN 55011:2009 section 6.2.2.3 instructs you to normalise the > measured data to the specified distance in the standard > - EN 55032:2015 section 9 instructs you to adjust the limits (in fact > it gives limits for 3 and 10m which are 10 dB apart and not 10.45dB apart > if you extrapolate using 20LogD) > - ANSI 63-4:2014 instructs you to extrapolate the results > > > > If the standard or test method doesn’t specify, I guess the important > thing is to be clear in the report as to what’s been done. > > > > Regards > > Charlie > > > > *Charlie Blackham* > > *Sulis Consultants Ltd* > > *Tel: +44 (0)7946 624317* > > *Web: https://sulisconsultants.com/ <https://sulisconsultants.com/> * > > Registered in England and Wales, number 05466247 > > > > *From:* itl-emc user group <itl...@itl.co.il> <itl...@itl.co.il> > *Sent:* 28 October 2019 06:37 > *To:* EMC-PSTC@LISTSERV.IEEE.ORG > *Subject:* [PSES] Reading or Limit Conversion? > > > > A number of standards list radiated emission limits in the frequency range > of 30-1000 MHz for test distance greater than 3 or 10 meters. > > Testing is normally performed at either 3 meters or 10 meters on an Open > Area Test Site. > > A question has arisen concerning reporting the test results in these cases. > > Any opinions concerning which should be converted: > > a. Convert the limit to the relevant test distance (3 meters or 10 > meters) by adding correction factor or > > b. Convert the reading to the unit and test distance listed in the > standard (convert dBµV to µV and add correction factor for distance) > > On some occasions I have seen option b. above used. > > Which option is preferable? > > All opinions welcome > > > > *Regards,* > > *David Shidlowsky* | Technical Reviewer > > *Address* 1 Bat-Sheva St. LOD 7120101 Israel > > *Tel* 972-8-9186113 *Fax* 972-8-9153101 > > *Mail* : dav...@itlglobal.org/dav...@itl.co.il/e...@itl.co.il *Web* > www.itlglobal.org > > > > *ITL Waze: *https://waze.com/ul/hsv8vccn2j > > > > *Fill out Customer* *Satisfaction Survey* > <http://app.sqm.co.il/SitePages/Questionnaire.aspx> > > *Global Certifications You Can Trust * > > This e-mail message may contain privileged or confidential information. > > If you are not the intended recipient, you may not disclose, use, > disseminate, distribute, copy or rely upon this message or attachment in > any way. If you received this e-mail message in error, please return by > forwarding the message and its attachments to the sender. > > > > > > - > ---------------------------------------------------------------- > > 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 < > emc-p...@ieee.org> > > 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://www.ieee-pses.org/list.html (including how to > unsubscribe) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > > - > ---------------------------------------------------------------- > > 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 < > emc-p...@ieee.org> > > 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://www.ieee-pses.org/list.html (including how to > unsubscribe) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > > - > ---------------------------------------------------------------- > > 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 < > emc-p...@ieee.org> > > 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://www.ieee-pses.org/list.html (including how to > unsubscribe) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > - > ---------------------------------------------------------------- > > 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 < > emc-p...@ieee.org> > > 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://www.ieee-pses.org/list.html (including how to > unsubscribe) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > -- Douglas E Powell doug...@gmail.com http://www.linkedin.com/in/dougp01 - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> 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://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
