I have been asked to comment on what improvement might be expected in changing the design of an equipment lid from:
A flat lid sat on the edges of the box, where the gaps between fasteners can be modelled as a simple aperture, where the attenuation decreases linearly with log(f) to zero at a half wavelength. To: A stepped lid, with the lid sat on the edges, and with the projection extending below the inner edge of the box.This removes the 'line of sight' gap into the enclosure. Does this improve the attenuation? Intuitively it should, but if the leakage occurs because of the interruption in shielding conductivity and hence current flow at the seam, it won't. Does anybody have any references to analyses of the above, or comments, please? (No emi gaskets are used btw). Thanks, Jeff Chambers Dr Jeff Chambers Westbay Technology Ltd Main St Baycliff Ulverston Cumbria LA12 9RN England Tel: 01229 869 108 Fax: 01229 869 108 http://www.westbay.ndirect.co.uk This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
