HI Dennis, I did not in anyway state that table top size should dictate set-up. Wendy's EUT has no cables, it's 10cm by 10cm: A non issue.
There are rules for what has to reside on the table and their placement in terns of separation. I believe it's also addressed when a set up is too big for a table. So this is all covered. The crux of my concern is that an assessor is wasting everyone's time for a non-event, time equals $$$$$$$. It gives credence to folks like Ken ( who I count as a very good friend ) who are not fans of the assessing process. And in cases like this, I agree with him. For all the pontificating going on, nominal means big enough to hold your set-up in accordance with placement rules. Height means 80 cm. Cheers, Derek. On 10/11/2011 2:07 PM, Dennis Ward wrote: > 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. 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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]>
