I agree with Andy. ITO coating has a surface resistivity of 14Ohms/sq inch. You could probably get just as much surface resistivity from a coating of dust :-)
ITO coatings are good at dissipating static; but I think that they are pretty much useless for shielding. I shudder to think of how naïve we were back in 1995 when this whole EMC (CE marking) kick began. We had one product with a window about 2" x 2". We had the window ITO coated. We spaced mounting screws every 1/2" around its edge and then used conductive RTV between the edge and the Aluminum panel into which it mounted. We took a $2 window assembly and turned it into a $50 window assembly. (we did this on the advice of someone we trusted) I looked into it a little while later and found the above facts regarding the surface resistivity of the ITO coating. We would have done just as much good by flushing money down the toilet. I would recommend a window with a fine, high mu wire (monel?) mesh shield. Tecknit and Chomerics make some shielded windows like this. Best regards, Chris Maxwell From: [email protected] mailto:[email protected]] On Behalf Of Barker, Neil Sent: Thursday, September 16, 2004 3:44 AM To: 'Price, Andrew P (UK Basildon)'; Emc-Pstc (E-mail) Subject: RE: Germanium & ITO Window shielding effectiveness Andy, While I have no objective evidence on this subject, I would not expect either of these to be particularly effective against magnetic fields as they are both thin films of fairly high resistivity. I suspect that it could be one of our products behind these windows, so is there any way that we can help? Best regards, Neil R. Barker C.Eng. MIEE FSEE MIEEE Manager Compliance Engineering e2v technologies (uk) ltd 106 Waterhouse Lane Chelmsford Essex CM1 2QU UK Tel: +44 (0)1245 453616 Fax: +44 (0)1245 453410 e-mail: [email protected] Web: http://www.e2v.com From: Price, Andrew P (UK Basildon) [mailto:[email protected]] Sent: 16 September 2004 08:21 To: Emc-Pstc (E-mail) Subject: Germanium & ITO Window shielding effectiveness Hello group. Can anyone help with finding information on shielding effectiveness of Germanium and ITO coated windows against magnetic fields? Regards Andy Andrew Price Principal Development Engineer (EMC Specialist) BAE SYSTEMS Avionics A125 Christopher Martin Road Basildon, Essex SS14 3EL tel: +44 (0) 1268 883308 email: [email protected] ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ******************************************************************** 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
