The only thing right about that post is the disclaimer, and that is only if you have an odd sense of humor. RE limits are set to protect broadcast radio reception, while RI/RS limits are set to bracket intentional transmitters. The margin between receivers and transmitters is between femto- and picowatt sensitivity and Watt or higher level transmission. If you make the apples to rocks comparison of RE to RI/RS limits the “margins” you come up with are on the order of 80 dB or higher. Is there another engineering discipline that enforces that sort of margin? Can you envision a bridge or building built with such margins? Would an airplane ever get built, much less leave the ground? And that Ares rocket that just launched successfully yesterday? What would lift-off look like with an 80 dB increase in mass, huh?
Granted the previous post was in jest, but too many people take that sort of thing at face value. This is embarrassing to the profession. Ken Javor Phone: (256) 650-5261 ________________________________ From: "Ilarina, Alvin" <[email protected]> List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: Fri, 30 Oct 2009 10:30:53 -0700 To: "Kunde, Brian" <[email protected]>, <[email protected]> Conversation: Where does 3V/m & 10V/m in RI come from? Subject: RE: Where does 3V/m & 10V/m in RI come from? IIRC the radiated immunity limits are set at X dB of something above the emissions limits creating a guard band. The theory being that there is a built in tolerance between the allowable emissions in the field and the level at which equipment is supposed to begin to be susceptible. I think I heard this explanation off-line from one of the “old men of EMC” at one of our conferences/symposiums years ago. We were most likely consuming alcohol at the time. This might just be urban legend. Alvin Disclaimer: The contents reflect the opinion of the author and are meant for entertainment purposes only. ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Kunde, Brian Sent: Thursday, October 29, 2009 10:18 AM To: [email protected] Subject: Where does 3V/m & 10V/m in RI come from? Simple question, where does the 1V/m, 3V/m and 10V/m test levels come from in the Radiated Immunity standards such as IEC/EN61000-4-3? Is there some real-world rf source that correlates to these levels? Thanks for the history lesson. The Other Brian _________________________ LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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]> - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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]> - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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]>
