Are we talking ohms or ohms per square? If it's ohms per square, .3 or .4 seems a little high for a metal sheet. Depending upon alot of factors, I'm used to Cu conductive coating on plastic running roughly just a little less than this and Ni conductive coating on plastic running just under an ohm.
Doug On Wed, 14 Oct 1998 b...@namg.us.anritsu.com wrote: > Hi Nancy, > > The following is my two cents worth. Please correct me. > >I have done a ohms test on the two materials. Both testing at .3 to .4 > ohms. > > My customer has already gone through their EMI Testing... > > It seems to me that only data of .3 and .4 ohms is not enough. We still > don't know the thickness of the coating, and also the data is only DC value > instead of RF value. Do you know how much margins of the EMI test your > customer has got with the original case? Even though we know all necessary > data, it's still very hard to say what role the conductivity plays in the > final EMI profile of the EUT, which depends on too many parameters. > > We have to do some test. If your customer was reluctant to redo the EMI > test, can you suggest a Shielding Effectiveness (SE) comparison test? The > test needs only two empty cases with a comb generator inside. The SE test > results are straightforward to convince your customer. > > Best Regards, > Barry Ma > > > ------------- > Original Text > From: <ed.pr...@cubic.com>, on 10/14/98 1:17 PM: > Hello Group! > > The following is a non-member post which was submitted to the admins, but > which really ought to be posted. (If you post a reply, remember to copy > Ludvigsen, but not me.) > > ------------------------ > From: Nancy Ludvigsen <nludvig...@emtengineering.com> > Subject: Conductivity Question > Date: Wed, 14 Oct 1998 15:53:56 -0500 > To: "'ed.pr...@cubic.com'" <ed.pr...@cubic.com>, > "'j...@gwmail.monarch.com'" <j...@gwmail.monarch.com> > > > > Hi Guys: I am a manufacturers rep. for a sheet metal fabricator. I have > a customer that is currently manufacturing an enclosure our or Galvannel. > This unit is welded and they are not currently painting over the welded > areas. This will cause corrosion over time. > > > > I am suggesting that they go to a zinc plated cold rolled steel for a > better finish, and also our buying power is suited for steel. > > > > My customer has already gone through their EMI Testing and is hesitant to > change to zinc plated cold rolled steel because they do not know the > difference in conductivity between the two materials. > > > > I have done a ohms test on the two materials. Both testing at .3 to .4 > ohms. > > > > Can you direct me to a source to get more information on the conductivity > of the two metal finishes? Or give me more direction as to how to address > this issue? > > > > Any information is greatly appreciated. Thank you in advance. > > > > Nancy > > > > > -------------------------- > Ed Price > ed.pr...@cubic.com > Electromagnetic Compatibility Lab > Cubic Defense Systems > San Diego, CA. USA > 619-505-2780 > Date: 10/14/1998 > Time: 12:17:52 > -------------------------- > > > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > j...@gwmail.monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). > > > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > j...@gwmail.monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). > > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
