Re: [PSES] LISN Calibration Measurement Uncertainty
All, As always - thanks for the feedback and discussion. Learn a lot from this forum Best regards, Mac From: Ken Javor <ken.ja...@emccompliance.com> To: EMC-PSTC@LISTSERV.IEEE.ORG Sent: Wednesday, September 13, 2017 8:57 AM Subject: Re: [PSES] LISN Calibration Measurement Uncertainty I assumed that since uncertainty was in question, that this was some sort of CISPR 22 or similar quest, so 150 kHz and up, and not CISPR 25. If it were CISPR 25, then it is a low impedance at 150 kHz as Tom points out, but using the technique I suggested, excellent accuracy may still be had. Ken Javor Phone: (256) 650-5261 > From: "T.Sato" <vef00...@nifty.com> > Reply-To: "T.Sato" <vef00...@nifty.com> > Date: Wed, 13 Sep 2017 22:09:36 +0900 > To: <EMC-PSTC@LISTSERV.IEEE.ORG> > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > On Tue, 12 Sep 2017 10:13:26 -0500, > Ken Javor <ken.ja...@emccompliance.com> wrote: > >> There shouldn't be a lower impedance issue, because from 150 kHz up the LISN >> is very close to 50 ohms. And once the LISN coil impedance is well above 50 >> ohms, the measured LISN impedance should be 50 ohms in parallel with the >> bleeder resistor, which is essentially 50 ohms. The only affect is if there > ... > > I think: > > o 50 ohms / 50 uH + 5 ohms LISN has impedance spec down to 9 kHz, > and its EUT port impedance is 5 ohms + j2.8 ohms at 9 kHz. > > o Automotive 5 uH LISN has impedance spec down to 150 kHz, and its > EUT port impedance is j4.7 ohms at 150 kHz. > > Regards, > Tom > > -- > Tomonori Sato <vef00...@nifty.com> > URL: http://t-sato.in.coocan.jp > > >>> From: "T.Sato" <vef00...@nifty.com> >>> Reply-To: "T.Sato" <vef00...@nifty.com> >>> Date: Tue, 12 Sep 2017 21:58:54 +0900 >>> To: <EMC-PSTC@LISTSERV.IEEE.ORG> >>> Subject: Re: [PSES] LISN Calibration Measurement Uncertainty >>> >>> On Mon, 11 Sep 2017 16:32:09 +, >>> Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: >>> >>>> We are interested in doing some in-house LISN calibrations (impedance >>>> verification only using network analyzer) and need to develop an >>>> uncertainty >>>> budget. >>>> Does anyone happen to have a budget you could share with us? We will go >>>> through the exercise of calculating ourself but if there is one out there >>>> would appreciate it if you could share. >>> >>> I think the major contributions would be: >>> >>> o network analyzer (VNA?); >>> o calibration jig which will be required to connect coax to the LISN >>> terminals. >>> >>> Other possible contributions such as resolution and repeatability may also >>> need to be considered, even if they are relatively minor. >>> >>> >>> For lower impedance, network analyzers may have relatively large impedance >>> measurement uncertainty: >>> >>> >>> http://www.keysight.com/main/editorial.jspx?cc=ES=spa=102148:eps >>> g: >>> faq=-11143.0.00=102148:epsg:faq >>> >>> Regards, >>> Tom >>> >>> -- >>> Tomonori Sato <vef00...@nifty.com> >>> URL: http://t-sato.in.coocan.jp >>> >>> - >>> >>> 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> >> >> - >> ---
Re: [PSES] LISN Calibration Measurement Uncertainty
I assumed that since uncertainty was in question, that this was some sort of CISPR 22 or similar quest, so 150 kHz and up, and not CISPR 25. If it were CISPR 25, then it is a low impedance at 150 kHz as Tom points out, but using the technique I suggested, excellent accuracy may still be had. Ken Javor Phone: (256) 650-5261 > From: "T.Sato" <vef00...@nifty.com> > Reply-To: "T.Sato" <vef00...@nifty.com> > Date: Wed, 13 Sep 2017 22:09:36 +0900 > To: <EMC-PSTC@LISTSERV.IEEE.ORG> > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > On Tue, 12 Sep 2017 10:13:26 -0500, > Ken Javor <ken.ja...@emccompliance.com> wrote: > >> There shouldn't be a lower impedance issue, because from 150 kHz up the LISN >> is very close to 50 ohms. And once the LISN coil impedance is well above 50 >> ohms, the measured LISN impedance should be 50 ohms in parallel with the >> bleeder resistor, which is essentially 50 ohms. The only affect is if there > ... > > I think: > > o 50 ohms / 50 uH + 5 ohms LISN has impedance spec down to 9 kHz, > and its EUT port impedance is 5 ohms + j2.8 ohms at 9 kHz. > > o Automotive 5 uH LISN has impedance spec down to 150 kHz, and its > EUT port impedance is j4.7 ohms at 150 kHz. > > Regards, > Tom > > -- > Tomonori Sato <vef00...@nifty.com> > URL: http://t-sato.in.coocan.jp > > >>> From: "T.Sato" <vef00...@nifty.com> >>> Reply-To: "T.Sato" <vef00...@nifty.com> >>> Date: Tue, 12 Sep 2017 21:58:54 +0900 >>> To: <EMC-PSTC@LISTSERV.IEEE.ORG> >>> Subject: Re: [PSES] LISN Calibration Measurement Uncertainty >>> >>> On Mon, 11 Sep 2017 16:32:09 +, >>> Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: >>> >>>> We are interested in doing some in-house LISN calibrations (impedance >>>> verification only using network analyzer) and need to develop an >>>> uncertainty >>>> budget. >>>> Does anyone happen to have a budget you could share with us? We will go >>>> through the exercise of calculating ourself but if there is one out there >>>> would appreciate it if you could share. >>> >>> I think the major contributions would be: >>> >>> o network analyzer (VNA?); >>> o calibration jig which will be required to connect coax to the LISN >>> terminals. >>> >>> Other possible contributions such as resolution and repeatability may also >>> need to be considered, even if they are relatively minor. >>> >>> >>> For lower impedance, network analyzers may have relatively large impedance >>> measurement uncertainty: >>> >>> >>> http://www.keysight.com/main/editorial.jspx?cc=ES=spa=102148:eps >>> g: >>> faq=-11143.0.00=102148:epsg:faq >>> >>> Regards, >>> Tom >>> >>> -- >>> Tomonori Sato <vef00...@nifty.com> >>> URL: http://t-sato.in.coocan.jp >>> >>> - >>> >>> 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> >> >> - >> >> 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 searchabl
Re: [PSES] LISN Calibration Measurement Uncertainty
On Tue, 12 Sep 2017 10:13:26 -0500, Ken Javor <ken.ja...@emccompliance.com> wrote: > There shouldn't be a lower impedance issue, because from 150 kHz up the LISN > is very close to 50 ohms. And once the LISN coil impedance is well above 50 > ohms, the measured LISN impedance should be 50 ohms in parallel with the > bleeder resistor, which is essentially 50 ohms. The only affect is if there ... I think: o 50 ohms / 50 uH + 5 ohms LISN has impedance spec down to 9 kHz, and its EUT port impedance is 5 ohms + j2.8 ohms at 9 kHz. o Automotive 5 uH LISN has impedance spec down to 150 kHz, and its EUT port impedance is j4.7 ohms at 150 kHz. Regards, Tom -- Tomonori Sato <vef00...@nifty.com> URL: http://t-sato.in.coocan.jp >> From: "T.Sato" <vef00...@nifty.com> >> Reply-To: "T.Sato" <vef00...@nifty.com> >> Date: Tue, 12 Sep 2017 21:58:54 +0900 >> To: <EMC-PSTC@LISTSERV.IEEE.ORG> >> Subject: Re: [PSES] LISN Calibration Measurement Uncertainty >> >> On Mon, 11 Sep 2017 16:32:09 +, >> Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: >> >>> We are interested in doing some in-house LISN calibrations (impedance >>> verification only using network analyzer) and need to develop an uncertainty >>> budget. >>> Does anyone happen to have a budget you could share with us? We will go >>> through the exercise of calculating ourself but if there is one out there >>> would appreciate it if you could share. >> >> I think the major contributions would be: >> >> o network analyzer (VNA?); >> o calibration jig which will be required to connect coax to the LISN >> terminals. >> >> Other possible contributions such as resolution and repeatability may also >> need to be considered, even if they are relatively minor. >> >> >> For lower impedance, network analyzers may have relatively large impedance >> measurement uncertainty: >> >> >> http://www.keysight.com/main/editorial.jspx?cc=ES=spa=102148:epsg: >> faq=-11143.0.00=102148:epsg:faq >> >> Regards, >> Tom >> >> -- >> Tomonori Sato <vef00...@nifty.com> >> URL: http://t-sato.in.coocan.jp >> >> - >> >> 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> > > - > > 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> - 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>
Re: [PSES] LISN Calibration Measurement Uncertainty
There shouldn't be a lower impedance issue, because from 150 kHz up the LISN is very close to 50 ohms. And once the LISN coil impedance is well above 50 ohms, the measured LISN impedance should be 50 ohms in parallel with the bleeder resistor, which is essentially 50 ohms. The only affect is if there is a parasitic that tanks with the coil to lower the total impedance to something closer to 50 ohms. That shouldn't be the case down the road if not when acquired, unless the LISN is damaged. So there really shouldn't be an issue here. Also, not familiar with modern VNAs (my HP 4195A has a max output of 15 dBm, or 122 dBuV across 50 ohms), but if I were using a signal generator and a spectrum analyzer, I could use quite high potentials (3 volts or more) and very flat current probe with say 0.1 or 1 ohm transfer impedance, to get numbers well above my noise floor, and a current probe with flat and low transfer impedance is very accurate because the value depends not on the construction of the probe but on the loading resistance, which is much easier to get to a specific value, just like the 50 ohms of the LISN has been noted in this thread to not be part of the LISN construction, but the load placed on it by a spectrum analyze or a dummy load of great precision. And the spectrum analyzer as a load must have at least 10 dB internal or external attenuation selected in order to give assurance that it looks like 50 ohms. Ken Javor Phone: (256) 650-5261 > From: "T.Sato" <vef00...@nifty.com> > Reply-To: "T.Sato" <vef00...@nifty.com> > Date: Tue, 12 Sep 2017 21:58:54 +0900 > To: <EMC-PSTC@LISTSERV.IEEE.ORG> > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > On Mon, 11 Sep 2017 16:32:09 +, > Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: > >> We are interested in doing some in-house LISN calibrations (impedance >> verification only using network analyzer) and need to develop an uncertainty >> budget. >> Does anyone happen to have a budget you could share with us? We will go >> through the exercise of calculating ourself but if there is one out there >> would appreciate it if you could share. > > I think the major contributions would be: > > o network analyzer (VNA?); > o calibration jig which will be required to connect coax to the LISN > terminals. > > Other possible contributions such as resolution and repeatability may also > need to be considered, even if they are relatively minor. > > > For lower impedance, network analyzers may have relatively large impedance > measurement uncertainty: > > > http://www.keysight.com/main/editorial.jspx?cc=ES=spa=102148:epsg: > faq=-11143.0.00=102148:epsg:faq > > Regards, > Tom > > -- > Tomonori Sato <vef00...@nifty.com> > URL: http://t-sato.in.coocan.jp > > - > > 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> - 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>
Re: [PSES] LISN Calibration Measurement Uncertainty
On Mon, 11 Sep 2017 16:32:09 +, Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: > We are interested in doing some in-house LISN calibrations (impedance > verification only using network analyzer) and need to develop an uncertainty > budget. > Does anyone happen to have a budget you could share with us? We will go > through the exercise of calculating ourself but if there is one out there > would appreciate it if you could share. I think the major contributions would be: o network analyzer (VNA?); o calibration jig which will be required to connect coax to the LISN terminals. Other possible contributions such as resolution and repeatability may also need to be considered, even if they are relatively minor. For lower impedance, network analyzers may have relatively large impedance measurement uncertainty: http://www.keysight.com/main/editorial.jspx?cc=ES=spa=102148:epsg:faq=-11143.0.00=102148:epsg:faq Regards, Tom -- Tomonori SatoURL: http://t-sato.in.coocan.jp - 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 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 Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] LISN Calibration Measurement Uncertainty
I'm afraid that one cannot assume that our ancestors were either all-knowing or idiots. They were people, just like us, and they got it right mostly, but not always. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Tuesday, September 12, 2017 12:37 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Perhaps all that is needed is to know is the Insertion Loss of the LISN. Some manufacturers provide this for every s/n. The LISN is only there to provide a known impedance to the source of emission so that RF current can be measured with repeatability. I do understand that CM and DM currents will have different (and unknown) source impedance and that those impedances will be a function of frequency, but I feel that's beside the point. I have to assume the folks at CISPR understood those topics and that they likely deliberated long and hard and did lots of measurements both in the lab and in the field before agreeing on the LISN as a standard transducer for the evaluation of conducted RF emission. If there were something fundamentally wrong with the method of measurement, I suspect it would have been uncovered long ago. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 4:10 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty The point of the cm vs. dm discussion is that the effect of LISN impedance is not so important for dm as for cm, speaking very generally, so that the effect of uncertainty in LISN impedance on dm emissions is less than for cm. But we don't separately measure cm and dm, so we don't know, looking at any specific signal, what the uncertainty is, even if we have nailed down the uncertainty of the LISN impedance. And you don't need two LISNs to separate modes, but that is another discussion. Ken Javor Phone: (256) 650-5261 - 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> - 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>
Re: [PSES] LISN Calibration Measurement Uncertainty
No criticism of how a LISN is calibrated. That wasn't the point. The point was that LISN impedance uncertainty affects the measurement of conducted emissions differently by mode, so that the overall uncertainty of the measurement of CE is different from that of the LISN impedance. Also, while the point of a 50 uH LISN is in fact to provide that impedance, the original limit was based on the rf susceptibility of radios operating below 30 MHz, and that susceptibility was to the rf potential caused by various electronic loads. It wasn't about current at all. Ken Javor Phone: (256) 650-5261 > From: Ralph McDiarmid <ralph.mcdiar...@schneider-electric.com> > Date: Mon, 11 Sep 2017 23:36:35 + > To: Ken Javor <ken.ja...@emccompliance.com>, "EMC-PSTC@LISTSERV.IEEE.ORG" > <EMC-PSTC@LISTSERV.IEEE.ORG> > Conversation: [PSES] LISN Calibration Measurement Uncertainty > Subject: RE: [PSES] LISN Calibration Measurement Uncertainty > > Perhaps all that is needed is to know is the Insertion Loss of the LISN. Some > manufacturers provide this for every s/n. > > The LISN is only there to provide a known impedance to the source of emission > so that RF current can be measured with repeatability. I do understand that > CM and DM currents will have different (and unknown) source impedance and that > those impedances will be a function of frequency, but I feel that's beside the > point. > > I have to assume the folks at CISPR understood those topics and that they > likely deliberated long and hard and did lots of measurements both in the lab > and in the field before agreeing on the LISN as a standard transducer for the > evaluation of conducted RF emission. > > If there were something fundamentally wrong with the method of measurement, I > suspect it would have been uncovered long ago. > > Ralph McDiarmid > Product Compliance > Engineering > Solar Business > Schneider Electric > > > From: Ken Javor [mailto:ken.ja...@emccompliance.com] > Sent: Monday, September 11, 2017 4:10 PM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > The point of the cm vs. dm discussion is that the effect of LISN impedance is > not so important for dm as for cm, speaking very generally, so that the effect > of uncertainty in LISN impedance on dm emissions is less than for cm. But we > don't separately measure cm and dm, so we don't know, looking at any specific > signal, what the uncertainty is, even if we have nailed down the uncertainty > of the LISN impedance. And you don't need two LISNs to separate modes, but > that is another discussion. > > > Ken Javor > Phone: (256) 650-5261 > - 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>
Re: [PSES] LISN Calibration Measurement Uncertainty
Perhaps all that is needed is to know is the Insertion Loss of the LISN. Some manufacturers provide this for every s/n. The LISN is only there to provide a known impedance to the source of emission so that RF current can be measured with repeatability. I do understand that CM and DM currents will have different (and unknown) source impedance and that those impedances will be a function of frequency, but I feel that's beside the point. I have to assume the folks at CISPR understood those topics and that they likely deliberated long and hard and did lots of measurements both in the lab and in the field before agreeing on the LISN as a standard transducer for the evaluation of conducted RF emission. If there were something fundamentally wrong with the method of measurement, I suspect it would have been uncovered long ago. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 4:10 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty The point of the cm vs. dm discussion is that the effect of LISN impedance is not so important for dm as for cm, speaking very generally, so that the effect of uncertainty in LISN impedance on dm emissions is less than for cm. But we don't separately measure cm and dm, so we don't know, looking at any specific signal, what the uncertainty is, even if we have nailed down the uncertainty of the LISN impedance. And you don't need two LISNs to separate modes, but that is another discussion. Ken Javor Phone: (256) 650-5261 - 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>
Re: [PSES] LISN Calibration Measurement Uncertainty
The point of the cm vs. dm discussion is that the effect of LISN impedance is not so important for dm as for cm, speaking very generally, so that the effect of uncertainty in LISN impedance on dm emissions is less than for cm. But we don't separately measure cm and dm, so we don't know, looking at any specific signal, what the uncertainty is, even if we have nailed down the uncertainty of the LISN impedance. And you don't need two LISNs to separate modes, but that is another discussion. Ken Javor Phone: (256) 650-5261 > From: Ralph McDiarmid <ralph.mcdiar...@schneider-electric.com> > Reply-To: Ralph McDiarmid <ralph.mcdiar...@schneider-electric.com> > Date: Mon, 11 Sep 2017 22:32:14 + > To: <EMC-PSTC@LISTSERV.IEEE.ORG> > Conversation: [PSES] LISN Calibration Measurement Uncertainty > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > Sorry, I guess we drifted a little off topic, and that's my fault. If you > want to characterize a LISN for the purpose of defining an measurement > "uncertainty budget" then I suppose all that is needed is a carefully written > test procedure. I doubt a Network Analyzer is required, I think a signal > generator and a scope would suffice. > > What parameter of a LISN matters for determining its measurement uncertainty? > I can only think of the impedance "seen" the DUT. As the impedance gradually > moves away from the ideal 50 ohm resistive, then I think less signal reaches > the EMI receiver, and that is the "uncertainty" or maybe error is a better > term. I really cannot see how CM vs DM comes into play at all; the LISN > measures both as far as I know, so one cannot separate the two, without using > a second LISN connected to a second power pole of the DUT. I think save to > say that most DUTs will have a least two power poles, a "line" and a "neutral > for connection to the a.c. mains. > > I think some manufactures provide a graph or two plotting something (perhaps > insertion loss versus frequency) for that serial number. > > I hope that helped a little. > > Ralph McDiarmid > Product Compliance > Engineering > Solar Business > Schneider Electric > > > -Original Message- > From: John Woodgate [mailto:jmw1...@btinternet.com] > Sent: Monday, September 11, 2017 1:28 PM > To: Ralph McDiarmid <ralph.mcdiar...@schneider-electric.com>; > EMC-PSTC@LISTSERV.IEEE.ORG > Subject: RE: [PSES] LISN Calibration Measurement Uncertainty > > It's not quite as simple as it may appear. Mr Javor points out that it > measures two mixtures of DM and CM voltages, which is not helpful either in > fixing a design or in determining the consequent radiated emission (due to the > CM component alone). > > The 50 ohms is indeed the input resistance of the SA. But it's not necessarily > (not likely to be) the impedance looking back down the mains lead to the EUT. > All it does is to help produce consistent results, it doesn't do anything to > help the results to be representative of real world conditions. > > With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J > M Woodgate and Associates Rayleigh England > > UK is a sovereignty, not a Zollverein-ty > > -Original Message- > From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] > Sent: Monday, September 11, 2017 7:33 PM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > My understanding: > > A LISN seems to be a simple device, which has three ports: an input, an > output, and a sense port. The sense port connects to the spectrum analyzer or > EMI receiver, with the input port connecting to mains, and the output port > connecting to the power terminals of the device under test (DUT). > > What impedance is important? I assume it is that impedance which is "seen" > by the DUT when it is connected to the output port of the LISN. I think it is > that impedance which is 'stabilized' over a given bandwidth for the purpose of > a repeatable measurement environment. > > When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides > the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), > there will be reactance (inductive or capacitive) that begins to affect the > impedance seen by the DUT, which moves the load impedance further away from > the ideal 50 ohms. > > > Ralph McDiarmid > Product Compliance > Engineering > Solar Business > Schneider Electric > > > From: Ken Javor [mailto:ken.ja...@emccompliance.com] > Sent: Monday, September 11, 2017 10:21 AM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES
Re: [PSES] LISN Calibration Measurement Uncertainty
Sorry, I guess we drifted a little off topic, and that's my fault. If you want to characterize a LISN for the purpose of defining an measurement "uncertainty budget" then I suppose all that is needed is a carefully written test procedure. I doubt a Network Analyzer is required, I think a signal generator and a scope would suffice. What parameter of a LISN matters for determining its measurement uncertainty? I can only think of the impedance "seen" the DUT. As the impedance gradually moves away from the ideal 50 ohm resistive, then I think less signal reaches the EMI receiver, and that is the "uncertainty" or maybe error is a better term. I really cannot see how CM vs DM comes into play at all; the LISN measures both as far as I know, so one cannot separate the two, without using a second LISN connected to a second power pole of the DUT. I think save to say that most DUTs will have a least two power poles, a "line" and a "neutral for connection to the a.c. mains. I think some manufactures provide a graph or two plotting something (perhaps insertion loss versus frequency) for that serial number. I hope that helped a little. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric -Original Message- From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Monday, September 11, 2017 1:28 PM To: Ralph McDiarmid <ralph.mcdiar...@schneider-electric.com>; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] LISN Calibration Measurement Uncertainty It's not quite as simple as it may appear. Mr Javor points out that it measures two mixtures of DM and CM voltages, which is not helpful either in fixing a design or in determining the consequent radiated emission (due to the CM component alone). The 50 ohms is indeed the input resistance of the SA. But it's not necessarily (not likely to be) the impedance looking back down the mains lead to the EUT. All it does is to help produce consistent results, it doesn't do anything to help the results to be representative of real world conditions. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, September 11, 2017 7:33 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty My understanding: A LISN seems to be a simple device, which has three ports: an input, an output, and a sense port. The sense port connects to the spectrum analyzer or EMI receiver, with the input port connecting to mains, and the output port connecting to the power terminals of the device under test (DUT). What impedance is important? I assume it is that impedance which is "seen" by the DUT when it is connected to the output port of the LISN. I think it is that impedance which is 'stabilized' over a given bandwidth for the purpose of a repeatable measurement environment. When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), there will be reactance (inductive or capacitive) that begins to affect the impedance seen by the DUT, which moves the load impedance further away from the ideal 50 ohms. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 10:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn't correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don't measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <mailto:0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mailto:mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only
Re: [PSES] LISN Calibration Measurement Uncertainty
I agree that the AMN (LISN) is intended only to provide consistent (more or less) results, not to represent a real-world impedance at RF. I don't know how much that impedance changes from site to site; quite a lot I'll bet. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric -Original Message- From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Monday, September 11, 2017 1:28 PM To: Ralph McDiarmid <ralph.mcdiar...@schneider-electric.com>; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] LISN Calibration Measurement Uncertainty It's not quite as simple as it may appear. Mr Javor points out that it measures two mixtures of DM and CM voltages, which is not helpful either in fixing a design or in determining the consequent radiated emission (due to the CM component alone). The 50 ohms is indeed the input resistance of the SA. But it's not necessarily (not likely to be) the impedance looking back down the mains lead to the EUT. All it does is to help produce consistent results, it doesn't do anything to help the results to be representative of real world conditions. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, September 11, 2017 7:33 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty My understanding: A LISN seems to be a simple device, which has three ports: an input, an output, and a sense port. The sense port connects to the spectrum analyzer or EMI receiver, with the input port connecting to mains, and the output port connecting to the power terminals of the device under test (DUT). What impedance is important? I assume it is that impedance which is "seen" by the DUT when it is connected to the output port of the LISN. I think it is that impedance which is 'stabilized' over a given bandwidth for the purpose of a repeatable measurement environment. When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), there will be reactance (inductive or capacitive) that begins to affect the impedance seen by the DUT, which moves the load impedance further away from the ideal 50 ohms. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 10:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn't correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don't measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <mailto:0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mailto:mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - 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 <mailto: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
Re: [PSES] LISN Calibration Measurement Uncertainty
It's not quite as simple as it may appear. Mr Javor points out that it measures two mixtures of DM and CM voltages, which is not helpful either in fixing a design or in determining the consequent radiated emission (due to the CM component alone). The 50 ohms is indeed the input resistance of the SA. But it's not necessarily (not likely to be) the impedance looking back down the mains lead to the EUT. All it does is to help produce consistent results, it doesn't do anything to help the results to be representative of real world conditions. With best wishes DESIGN IT IN! OOO – Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, September 11, 2017 7:33 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty My understanding: A LISN seems to be a simple device, which has three ports: an input, an output, and a sense port. The sense port connects to the spectrum analyzer or EMI receiver, with the input port connecting to mains, and the output port connecting to the power terminals of the device under test (DUT). What impedance is important? I assume it is that impedance which is "seen" by the DUT when it is connected to the output port of the LISN. I think it is that impedance which is 'stabilized' over a given bandwidth for the purpose of a repeatable measurement environment. When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), there will be reactance (inductive or capacitive) that begins to affect the impedance seen by the DUT, which moves the load impedance further away from the ideal 50 ohms. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 10:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn't correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don't measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <mailto:0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mailto:mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - 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 <mailto: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 <mailto:sdoug...@ieee.org> Mike Cantwell <mailto:mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <mailto:j.bac...@ieee.org> David Heald <mailto:dhe...@gmail.com> __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is
Re: [PSES] LISN Calibration Measurement Uncertainty
My understanding: A LISN seems to be a simple device, which has three ports: an input, an output, and a sense port. The sense port connects to the spectrum analyzer or EMI receiver, with the input port connecting to mains, and the output port connecting to the power terminals of the device under test (DUT). What impedance is important? I assume it is that impedance which is "seen" by the DUT when it is connected to the output port of the LISN. I think it is that impedance which is 'stabilized' over a given bandwidth for the purpose of a repeatable measurement environment. When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), there will be reactance (inductive or capacitive) that begins to affect the impedance seen by the DUT, which moves the load impedance further away from the ideal 50 ohms. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 10:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn't correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don't measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <mailto:0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mailto:mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - 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 <mailto: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 <mailto:sdoug...@ieee.org> Mike Cantwell <mailto:mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <mailto:j.bac...@ieee.org> David Heald <mailto:dhe...@gmail.com> __ This email has been scanned by the Symantec Email Security.cloud service. __ - 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 <mailto: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 List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <mailto:sdoug...@ieee.org> Mike Cantwell <mailto:mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <mailto:j.bac...@ieee.org> David Heald <mailto:dhe...@gmail.com> -
Re: [PSES] LISN Calibration Measurement Uncertainty
Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn¹t correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don¹t measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - 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) 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>
[PSES] LISN Calibration Measurement Uncertainty
All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - 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 toAll 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 Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: