I can’t speak to the adhesive question, but a long time ago if you needed sub-microwave absorption, you were looking at pretty large cones. The longer the cone, the greater the moment arm exerting torque on the adhesive bond just >from gravity. Today, you get your sub-microwave absorption from a thin layer of ferrite tile, which is directly attached to the chamber wall. The very short cones needed to work above 1 GHz won’t have the moment arm pulling them off the ferrite tile. Also the latest hybrid absorber looks more like stiff bent paper or cardboard and has almost no mass at all. Ken Javor
Phone: (256) 650-5261 _____ From: Philo Beddo <[email protected]> List-Post: [email protected] Date: Sat, 17 Nov 2007 10:21:43 -0800 (PST) To: "[email protected]" <[email protected]> Subject: Semi-Anechoic Chamber Question Regards All, I was speaking with a co-worker in North America this past week, he mentioned, at times the absorber material (cones) may seperate from the walls of the chamber proper. I was curious about this as my employer is considering construction of a semi-anechoic facility in the near future. My understanding is that in some cases the absorber material will remain fixed on the walls for many years, and in other cases only two or three years before sagging and seperation become an issue. When we begin to specifiy and construct our facility, what performance should I expect over a 5-10 year period with respect to the bonding of the cones to the chamber proper? Is this an ongoing maintence issue with various contruction materials, or are there known defects in the adhesion process? Is there a process to check the existing absorbers after they are in place year over year? Finally, how will the chamber performance (EME and EMI) be compromised if the cones sag or become seperated from the chamber proper? Best regards, Ash. _____ Never miss a thing. Make Yahoo your homepage. <http://us.rd.yahoo.com/evt=51438/*http://www.yahoo.com/r/hs> <http://us.rd.yahoo.com/evt=51438/*http://www.yahoo.com/r/hs> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
