Re: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
Admittedly it is out of context (and refers to impulsive, wide band, emission) but you might use the precedent of CISPR14 Emission . Household Appliances, electric tools and similar apparatus which has a section 4.2 covering Discontinuous Disturbances. It is worth a look - but too detailed to summarise here. Richard Richard Marshall Laboratories, 30 Ox Lane, Harpenden, Herts.,AL5 4HE, UK +44 (0)1582 460815 http://www.design-emc.co.uk www.design-emc.co.uk Member of the EMC Industry Association From: Pawson, James [mailto:james.paw...@echostar.com] Sent: 26 March 2015 15:02 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? Dear group, When measuring emissions using a Quasi Peak detector are there any regulations or guidance concerning the amount of time one should dwell on a single frequency for a measurement? I know it depends on the nature of the signal. In this case, the signal of interest results in a burst of emissions of a high duty cycle followed by a long period (i.e. several minutes) of low duty cycle activity. If I use a QP detector and measure for 1 second just as the burst happens then I would get a high QP reading. If I measure in the steady state period I would get a lower QP reading. In this case, knowing the signals involves, would the intention to be to measure 1. one full representative cycle of emissions i.e. the initial burst and the low duty period after 2. during the maximum duty cycle only 3. during the steady state only I can imagine that the measurement difference between 1) and 3) in this case would be small as the level measured during the high duty period would have had time to decay down to the same level as the steady state due to the QP time constant. I'm asking this question in the context of both EN 55022 and FCC 15. Googling for quasi peak measurement time and similar phrases is not proving helpful Many thanks James Pawson - 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 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 sdoug...@ieee.org mailto:sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org mailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org mailto:j.bac...@ieee.org David Heald dhe...@gmail.com mailto: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] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
Thank you to everyone who responded and clarified the issue, it is much appreciated. Regards, James From: Pawson, James Sent: 26 March 2015 15:02 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? Dear group, When measuring emissions using a Quasi Peak detector are there any regulations or guidance concerning the amount of time one should dwell on a single frequency for a measurement? I know it depends on the nature of the signal. In this case, the signal of interest results in a burst of emissions of a high duty cycle followed by a long period (i.e. several minutes) of low duty cycle activity. If I use a QP detector and measure for 1 second just as the burst happens then I would get a high QP reading. If I measure in the steady state period I would get a lower QP reading. In this case, knowing the signals involves, would the intention to be to measure 1. one full representative cycle of emissions i.e. the initial burst and the low duty period after 2. during the maximum duty cycle only 3. during the steady state only I can imagine that the measurement difference between 1) and 3) in this case would be small as the level measured during the high duty period would have had time to decay down to the same level as the steady state due to the QP time constant. I'm asking this question in the context of both EN 55022 and FCC 15. Googling for quasi peak measurement time and similar phrases is not proving helpful Many thanks James Pawson - 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.orgmailto: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.orgmailto:sdoug...@ieee.org Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald dhe...@gmail.commailto: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] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
Yes, worst case means worst case. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. From: Rob Oglesbee [mailto:rogles...@radianresearch.com] Sent: Thursday, March 26, 2015 8:30 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? James, Since you are aware of it, you need to make sure you capture the max reading. Rob Oglesbee Radian Research (765) 449-5505 This message, and any attachments to it, may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are notified that any use, dissemination, distribution, copying, or communication of this message is strictly prohibited. If you have received this message in error, please notify the sender immediately by return e-mail or call 765-449-5500 and delete the message and any attachments. Thank you. From: Pawson, James [mailto:james.paw...@echostar.com] Sent: Thursday, March 26, 2015 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG mailto:EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? Dear group, When measuring emissions using a Quasi Peak detector are there any regulations or guidance concerning the amount of time one should dwell on a single frequency for a measurement? I know it depends on the nature of the signal. In this case, the signal of interest results in a burst of emissions of a high duty cycle followed by a long period (i.e. several minutes) of low duty cycle activity. If I use a QP detector and measure for 1 second just as the burst happens then I would get a high QP reading. If I measure in the steady state period I would get a lower QP reading. In this case, knowing the signals involves, would the intention to be to measure 1. one full representative cycle of emissions i.e. the initial burst and the low duty period after 2. during the maximum duty cycle only 3. during the steady state only I can imagine that the measurement difference between 1) and 3) in this case would be small as the level measured during the high duty period would have had time to decay down to the same level as the steady state due to the QP time constant. I’m asking this question in the context of both EN 55022 and FCC 15. Googling for “quasi peak measurement time” and similar phrases is not proving helpful Many thanks James Pawson - 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 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 sdoug...@ieee.org mailto:sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org mailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org mailto:j.bac...@ieee.org David Heald dhe...@gmail.com mailto: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 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] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
In one of my previous lives when I was engaged in EMI testing, QP testing was done manually using the HP Quasi Peak Adapter. I remember using a time period of 20 seconds for QP measurements, which was accepted by FCC. Regards Ravinder Ajmani HGST, a Western Digital company 5601 Great Oaks Pkwy San Jose, CA 95119-1003 ravinder.ajm...@hgst.commailto:ravinder.ajm...@hgst.com From: dward [mailto:dw...@pctestlab.com] Sent: Thursday, March 26, 2015 9:11 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? Yes, worst case means worst case. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. From: Rob Oglesbee [mailto:rogles...@radianresearch.com] Sent: Thursday, March 26, 2015 8:30 AM To: EMC-PSTC@LISTSERV.IEEE.ORGmailto:EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? James, Since you are aware of it, you need to make sure you capture the max reading. Rob Oglesbee Radian Research (765) 449-5505 This message, and any attachments to it, may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are notified that any use, dissemination, distribution, copying, or communication of this message is strictly prohibited. If you have received this message in error, please notify the sender immediately by return e-mail or call 765-449-5500 and delete the message and any attachments. Thank you. From: Pawson, James [mailto:james.paw...@echostar.com] Sent: Thursday, March 26, 2015 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORGmailto:EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? Dear group, When measuring emissions using a Quasi Peak detector are there any regulations or guidance concerning the amount of time one should dwell on a single frequency for a measurement? I know it depends on the nature of the signal. In this case, the signal of interest results in a burst of emissions of a high duty cycle followed by a long period (i.e. several minutes) of low duty cycle activity. If I use a QP detector and measure for 1 second just as the burst happens then I would get a high QP reading. If I measure in the steady state period I would get a lower QP reading. In this case, knowing the signals involves, would the intention to be to measure 1. one full representative cycle of emissions i.e. the initial burst and the low duty period after 2. during the maximum duty cycle only 3. during the steady state only I can imagine that the measurement difference between 1) and 3) in this case would be small as the level measured during the high duty period would have had time to decay down to the same level as the steady state due to the QP time constant. I’m asking this question in the context of both EN 55022 and FCC 15. Googling for “quasi peak measurement time” and similar phrases is not proving helpful Many thanks James Pawson - 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.orgmailto: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.orgmailto:sdoug...@ieee.org Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald dhe...@gmail.commailto:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post
Re: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
In message 99532047d6a52847ab271f822ae9efdc0177713...@cktexmb01.cds.int, dated Thu, 26 Mar 2015, Paasche, Dieter dieter.paas...@christiedigital.com writes: with the exception of any brief isolated high reading, which shall be ignored Too vague. Bad standard! Go to the naughty step. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
From CISPR 22 Section 6.2 6.1 Limits below 1 GHz The EUT shall meet the limits of Table 5 or Table 6 when measured at the measuring distance R in accordance with the methods described in Clause 10. If the reading on the measuring receiver shows fluctuations close to the limit, the reading shall be observed for at least 15 s at each measurement frequency; the highest reading shall be recorded, with the exception of any brief isolated high reading, which shall be ignored. We have had similar situation and tested the highest busts. I don't think you can classify the reading as a brief isolated high reading. Sincerely, Dieter Paasche Advanced Product Developer, Electrical CHRISTIE 809 Wellington Street North Kitchener, Ontario N2G 4Y7 Phone: +1 519-744-8005 Ext 7211 www.christiedigital.comhttp://www.christiedigital.com/ This e-mail message (including attachments, if any), is confidential. Any unauthorized use, distribution or disclosure is prohibited. If you have received this e-mail message in error, please notify the sender by reply e-mail or telephone and delete it and any attachments from your computer system and records. From: Pawson, James [mailto:james.paw...@echostar.com] Sent: Thursday, March 26, 2015 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? Dear group, When measuring emissions using a Quasi Peak detector are there any regulations or guidance concerning the amount of time one should dwell on a single frequency for a measurement? I know it depends on the nature of the signal. In this case, the signal of interest results in a burst of emissions of a high duty cycle followed by a long period (i.e. several minutes) of low duty cycle activity. If I use a QP detector and measure for 1 second just as the burst happens then I would get a high QP reading. If I measure in the steady state period I would get a lower QP reading. In this case, knowing the signals involves, would the intention to be to measure 1. one full representative cycle of emissions i.e. the initial burst and the low duty period after 2. during the maximum duty cycle only 3. during the steady state only I can imagine that the measurement difference between 1) and 3) in this case would be small as the level measured during the high duty period would have had time to decay down to the same level as the steady state due to the QP time constant. I'm asking this question in the context of both EN 55022 and FCC 15. Googling for quasi peak measurement time and similar phrases is not proving helpful Many thanks James Pawson - 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.orgmailto: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.orgmailto:sdoug...@ieee.org Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald dhe...@gmail.commailto: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] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
Dear group, When measuring emissions using a Quasi Peak detector are there any regulations or guidance concerning the amount of time one should dwell on a single frequency for a measurement? I know it depends on the nature of the signal. In this case, the signal of interest results in a burst of emissions of a high duty cycle followed by a long period (i.e. several minutes) of low duty cycle activity. If I use a QP detector and measure for 1 second just as the burst happens then I would get a high QP reading. If I measure in the steady state period I would get a lower QP reading. In this case, knowing the signals involves, would the intention to be to measure 1) one full representative cycle of emissions i.e. the initial burst and the low duty period after 2) during the maximum duty cycle only 3) during the steady state only I can imagine that the measurement difference between 1) and 3) in this case would be small as the level measured during the high duty period would have had time to decay down to the same level as the steady state due to the QP time constant. I'm asking this question in the context of both EN 55022 and FCC 15. Googling for quasi peak measurement time and similar phrases is not proving helpful Many thanks James Pawson - 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] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
In message cec6039c09630543852b1a8cfa0a0c790e0a3...@stwpiexc03.sats.corp, dated Thu, 26 Mar 2015, Pawson, James james.paw...@echostar.com writes: When measuring emissions using a Quasi Peak detector are there any regulations or guidance concerning the amount of time one should dwell on a single frequency for a measurement? This is a 'spirit and letter' matter. Emission limits are there to protect other services. So, in the spirit of the requirements, it is necessary to measure the 'worst case' (not the worst-worst-worst case, as some 'EMC crusaders' advocate). For your product, that is clearly during the 'burst' phase, even though the letter of the requirements may not cover this situation. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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] Quasi Peak - Length of Measurement Time for Final Spot Measurement?
James, Since you are aware of it, you need to make sure you capture the max reading. Rob Oglesbee Radian Research (765) 449-5505 This message, and any attachments to it, may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are notified that any use, dissemination, distribution, copying, or communication of this message is strictly prohibited. If you have received this message in error, please notify the sender immediately by return e-mail or call 765-449-5500 and delete the message and any attachments. Thank you. From: Pawson, James [mailto:james.paw...@echostar.com] Sent: Thursday, March 26, 2015 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Quasi Peak - Length of Measurement Time for Final Spot Measurement? Dear group, When measuring emissions using a Quasi Peak detector are there any regulations or guidance concerning the amount of time one should dwell on a single frequency for a measurement? I know it depends on the nature of the signal. In this case, the signal of interest results in a burst of emissions of a high duty cycle followed by a long period (i.e. several minutes) of low duty cycle activity. If I use a QP detector and measure for 1 second just as the burst happens then I would get a high QP reading. If I measure in the steady state period I would get a lower QP reading. In this case, knowing the signals involves, would the intention to be to measure 1. one full representative cycle of emissions i.e. the initial burst and the low duty period after 2. during the maximum duty cycle only 3. during the steady state only I can imagine that the measurement difference between 1) and 3) in this case would be small as the level measured during the high duty period would have had time to decay down to the same level as the steady state due to the QP time constant. I'm asking this question in the context of both EN 55022 and FCC 15. Googling for quasi peak measurement time and similar phrases is not proving helpful Many thanks James Pawson - 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 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 sdoug...@ieee.org mailto:sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org mailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org mailto:j.bac...@ieee.org David Heald dhe...@gmail.com mailto: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
