Derek True, if you have one device, no cables, no power and no support equipment. If you have anything else, then there are stated separation distances between devices, stated cable routing etc. Again, the standard is not written to the anomaly, but to the expected generalized configurations in which sufficient space must be given to accommodate expected support equipment, not just the EUT.
The reason you have a suggested/recommended/designated table size is to allow a standardized setup, standardized configuration, standardized separation and standardized cable manipulation. And, remember the subject line " Table Size in Emissions test - Intent" Dennis Ward Director of Engineering American Certification Body Certification Resource for the Wireless Industry http://www.acbcert.com 703-847-4700 fax 703-847-6888 direct - 703-880-4841 -----Original Message----- From: Derek Walton [mailto:[email protected]] Sent: Tuesday, October 11, 2011 11:50 AM To: Dennis Ward Cc: [email protected]; [email protected] Subject: Re: Table Size in Emissions test - Intent Dennis, Test set-up is independent of table size. Especially since we prove the table is not part of the equation.. Cheers, Derek. On 10/11/2011 1:20 PM, Dennis Ward wrote: > Yes, and you can get accredited to test only cameras in that configuration > if that is what you do and what you want. > > But the intent of a general scope of accreditation to ANSI C63.4 or C63.10 > (or any standard) is not the anomaly, but the general test configurations > specified in the standard. Consequently, unless you limit your testing > capabilities, going with the expected dimensions is simply easier, faster > and allows all configurations in test setup etc. > > > > Dennis Ward > > Director of Engineering > American Certification Body > Certification Resource for the Wireless Industry http://www.acbcert.com > 703-847-4700 fax 703-847-6888 > direct - 703-880-4841 > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of > [email protected] > Sent: Tuesday, October 11, 2011 10:52 AM > To: [email protected] > Subject: Re: Table Size in Emissions test - Intent > > When confronted with problems like this, I always try to determine the > intent of the particular statement in the test. To me, it is clear that > the intent is to fully support the EUT and associated equipment, with > cables dropping off the edges of the defined area, as needed. The table > should serve this support function and be invisible to RF. > > In the case of a small EUT with no cables, the intent is satisfied with a > table just large enough to support the EUT. Heck, for something like a > digital camera without cables, a threaded plastic rod coming up from the > turntable, screwed into the mounting hole in the bottom of the camera, > would be sufficient to support it and satisfy the intent. > > Of course, getting an auditor to understand the intent, as opposed to a > literal reading, might be difficult to do. > > Donald Borowski > Senior EMC Compliance Engineer > Schweitzer Engineering Labs > Pullman, Washington, USA > > > From: Derek Walton<[email protected]> > To: [email protected] > Cc: "'Grace Lin'"<[email protected]>, "'WNya'" > <[email protected]>, "'EMC-PSTC'"<[email protected]> > Date: 10/11/2011 10:12 AM > Subject: Re: Table Size in Emissions test > Sent by: [email protected] > > > > Sorry Dennis, > > you are not correct. Nominal means: > > b : of, being, or relating to a designated or theoretical size that may > vary from the actual. > > This is from Websters. > > As you indicate, there is NOTHING that says it has to be 1 by 1.5m > > I'm sorry to be so anal about this, but it is happening too much where > assessors are assessing to opinions and personal agendas. We must follow > the standard. Usually there are MUCH bigger fish to fry than quibbling > over something like this > > I repeat, again, that there is NOTHING that says the table SHALL be 1 by > 1.5m. Only then could a deficiency be written. > > Sincerely, > > Derek. > > > On 10/11/2011 11:43 AM, Dennis Ward wrote: > Both ANSI C63.10 and ANSI C63.4, the typical standards for which ISO17025 > accreditation is used, contain the following statement, ?Tabletop devices > shall be placed on a nonconducting platform, of nominal size 1 m by 1.5 m, > raised 80 cm above the reference ground plane. > > While a bit more open to variation due to size of equipment, CISPR 22 has > the statement ?Equipment intended for tabletop use shall be placed on a > non-conductive table. The size of the table will nominally be 1,5 m × 1,0 > m but may ultimately be dependent on the horizontal dimensions of EUT. > > So while you may challenge the accreditation organization, they are > correct, your table does not meet the ?nominal? size requirements for at > least the two standards ANSI C63.4 and C6310. > > Other standards may also have the nominal size issue as well. > > Thanks > Dennis Ward > > Director of Engineering > American Certification Body > Certification Resource for the Wireless Industry http://www.acbcert.com > 703-847-4700 fax 703-847-6888 > direct - 703-880-4841 > > From: [email protected] [mailto:[email protected]] On Behalf Of Grace Lin > Sent: Tuesday, October 11, 2011 4:16 AM > To: WNya > Cc: EMC-PSTC > Subject: Re: Table Size in Emissions test > > Wendy, > > When I look for an accredited ANSI C63.4 laboratory, I expect the > laboratory has the facility as stated in the standard, including a > standard size of the table as defined in the standard. For this reason, > unless the accreditation certificate bears a restriction note, I support > the auditor's comment. > > > From the other point of view, many manufacturers' laboratories are for > internal use only, including my employer's. For this reason, the auditor > may be willing to accept the smaller size of the table. The question is > how to determine if the laboratory is for internal use only (for testing > certain type of products). An example is Alcatel-Lucent's EMC laboratory > in New Jersey, USA. It opens to the general public. > > With regards, > Grace > > > On Mon, Oct 10, 2011 at 7:54 PM, WNya<[email protected]> wrote: > Dear Experts, > Recently my company went through the first ISO17025 audit. We have a table > smaller than the standard requirement of 1.5m x 1m since our products are > small, typically 10cm x 10cm x 10cm. The height of our table was 0.8m. The > auditor wanted us to change the table size to follow the standard. > What does it matter since we never use the extra space on the table? I do > agree we must keep to the height requirement since the floor is a ground > plane and thus it sets a fixed capacitance to the EUT and also controls > the lengths of any attached cables. > > Can we reject or challenge the auditor's request? Has anyone experience > the same situation? > > Sent from Wendy.Nya iPhone > > - > ---------------------------------------------------------------- > 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]> > > - > ---------------------------------------------------------------- > 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]> > - > ---------------------------------------------------------------- > 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]> > - > ---------------------------------------------------------------- > 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]> > > - > ---------------------------------------------------------------- > 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]> > > - > ---------------------------------------------------------------- > 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]> > - ---------------------------------------------------------------- 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]>
