>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.com<http://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.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>
