Following up on Brent’s reply, the CM current measured by the probe will be partially determined by the CM termination impedance which is 150 ohms in the CISPR setups. You can use an IEC 61000-4-6 EM clamp to approximate this with reasonably good results.
All the best James James Pawson Managing Director & EMC Problem Solver Unit 3 Compliance Ltd EMC : Environmental & Vibration : Electrical Safety : CE & UKCA : Consultancy <http://www.unit3compliance.co.uk/> www.unit3compliance.co.uk | <mailto:[email protected]> [email protected] +44(0)1274 911747 | +44(0)7811 139957 2 Wellington Business Park, New Lane, Bradford, BD4 8AL Registered in England and Wales # 10574298 For inquiries, bookings, and testing updates please send us an email on [email protected] <mailto:[email protected]> or call 01274 911747. Our lead times for testing and consultancy are typically 4-5 weeks. From: Brent DeWitt <[email protected]> Sent: 17 December 2024 21:54 To: [email protected] Subject: Re: [PSES] Conducted emission - LISN vs. current clamp >From my experience, I would seldom expect the current probe and the LISN to >show the same answer. The big difference is that the current probe is looking >at a fairly random termination impedance compared to the "Line Impedance >Stabilization Network", which is reasonably stable in its design. An >interesting experiment is to use the CM/DM choke on a power cord plugged into >a LISN and examine the differences, On 12/17/2024 4:27 PM, Ken Wyatt wrote: We’ll need a lot more information on what you’re testing, the test setup configuration and how you’re measuring DM and CM. Can you share some photos or screen captures? Usually there will be a difference between DM and CM current spectral response. Now Line and Neutral from a LISN will like look the same typically. Kenneth Wyatt Windsor, CO On Dec 17, 2024, at 13:46, [email protected] <mailto:[email protected]> wrote: Clamp is ok for investigate DM and CM currents. LISN for formal testing at lab. Right now, the plots of CM and DM currents are almost equal over the whole spectrum (10k – 30MHz). Surprise? In the same setup, using a LISN, the spectrum is quite different regarding peaks and waveform. I know the information from this test is defective, but do you have a first thought anyway? BR Amund _____ 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: https://www.mail-archive.com/[email protected]/ <https://www.mail-archive.com/[email protected]/%20> Website: https://ewh.ieee.org/soc/pses/ <https://ewh.ieee.org/soc/pses/> Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) <https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: [email protected] <mailto:[email protected]> Rick Linford at: [email protected] <mailto:[email protected]> For policy questions, send mail to: Jim Bacher at: [email protected] <mailto:[email protected]> _____ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC <https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1> &A=1 _____ 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: https://www.mail-archive.com/[email protected]/ <https://www.mail-archive.com/[email protected]/%20> Website: https://ewh.ieee.org/soc/pses/ <https://ewh.ieee.org/soc/pses/> Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) <https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: [email protected] <mailto:[email protected]> Rick Linford at: [email protected] <mailto:[email protected]> For policy questions, send mail to: Jim Bacher at: [email protected] <mailto:[email protected]> _____ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC <https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1> &A=1 _____ 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: https://www.mail-archive.com/[email protected]/ <https://www.mail-archive.com/[email protected]/%20> Website: https://ewh.ieee.org/soc/pses/ <https://ewh.ieee.org/soc/pses/> Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) <https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: [email protected] <mailto:[email protected]> Rick Linford at: [email protected] <mailto:[email protected]> For policy questions, send mail to: Jim Bacher at: [email protected] <mailto:[email protected]> _____ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC <https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1> &A=1 -- This email has been checked for viruses by AVG antivirus software. www.avg.com - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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