Hi and thanks for all the insightful emails. The way we perform the test in-house is... unmodulated > frequency set > level set from cal (instant application, no ramp) > apply modulation > dwell time > unmodulated > next freq I think we are all agreed that different test methods can result in different EUT behaviour. It would also appear that there is no consensus for an agreed method of testing.
My main line of enquiry was to clarify the test procedure. I have seen cases where applying the field suddenly results in a momentary disturbance to the EUT that disappears resulting in a stable operating EUT during the dwell time. A slow increase in the field does not result in this momentary disturbance. Lack of a directional coupler means that measuring the RF field in realtime is difficult in our case to see what is happening at the moment of applying the modulation and changing the level. I guess the dwell time starts as soon as a stable RF field has been established. I'm also going to investigate leaving the RF modulation on and redoing our test procedure to level set with the modulation on constantly to see what difference that makes. Many thanks James ________________________________ From: Pawson, James Sent: 20 August 2012 10:54 To: [email protected] Subject: [PSES] 61000-4-3: Rate of application of field Hello, I can't find any clauses in 61000-4-3 (radiated RF immunity) that deal with the rate of application of the RF field. My understanding is that the test is generally performed by setting the unmodulated carrier to the level contained within the calibration file and then suddenly applying the modulation. Is there any precedent for, or problem with, gradually increasing the modulated carrier field strength up to the required level instead of a more sudden application? I imagine a system like a mobile radio would involve a suddenly applied burst of RF when the transmitter is "keyed". Many thanks James - ---------------------------------------------------------------- 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: 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]<mailto:[email protected]>> Mike Cantwell <[email protected]<mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected]<mailto:[email protected]>> David Heald <[email protected]<mailto:[email protected]>> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
