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Date: | Wed, 23 Apr 1997 11:43:21 -0700 |
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Can anyone tell me how to convert Megohms / sq. inch into (g / sq. cm ?
Also, section 5.0 of IPC-A-600E states the resistance limitations for =
solvent resistivity to not be less than 2 x 10 to the 6th power / cm. =
Should not the cm be squared to provide a surface area? All help is =
appreciated.
Thanks,
Ed Cosper
Ed: I think you may be mixing apples, oranges and units.
Volume resistivity is measured in ohm-cm. This can be correlated to
milligrams of ionic material contained in a liter of extract solution(ppm).
Salt, NaCl is used as the equivalency factor. A resistivity reading of
two megohm-cm is equivalent to 1.56ug/cm2 of NaCl in the extract solution.
The higher the resistivity reading the lower the equivalent salt
content.
If you are trying to convert from sq.in to sq. cm for NaCl equivalence
use the following: 10.06ug/in2 = 1.56ug/cm2,BTW these are upper acceptability
limits. Hope this helps if not give me a call.
Regards
Michael Barmuta
Staff Engineer
Fluke Corp.
Everett Wa.
206-356-6076
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