Q on rating in volts per mil

Type of conformal coating amd mfr?

RL

Of course it is unless you prefer kV/inch.

See

Perhaps the manufacturer thinks that the meaningful rating is the breakdown voltage that can be attained with the material when it is properly applied.

Since that "proper application" would include some minimum thickness, you're left with a voltage.

This, in turn, means that if you're intending to do some application that _doesn't_ conform (as it were) to this minimum thickness, then you're either (a) smarter than the manufacturer, or (b) dumber than the manufacturer. It's always hard to tell which in these cases, because the stuff has probably been in production since 1953, and all the folks that actually knew did the math on it are dust.

You could try calling them up and asking how many coats you need to get a withstanding voltage of whatever it is you're looking for. Sometimes that'll prompt a response from someone who actually understands what's going on and why, sometimes that just gets you shrugs (or worse, some idiot sales man telling you what he thinks you want to hear so he can sell you a case of the stuff).

Asking "could you recommend a competitor who's actually competent" will piss them off, but might make you feel better.

Yes.

Jamie

At least the "specification" of Dielectric Withstand Voltage, volts per MIL-I-46058C >1,500 is semi-access able in that the MIL spec appears to specify 2mil coating (not eXplicitly clear,tho).

HumiSeal 1B73? Aerosol Conformal Coating

Wow! The rating is "Yes." volts per mil. Thanks.

I think D149 is done with a 0.100" gap.

Cheers

per

What part of that is a standard test unit for the past 40 years or more don't you understand?

?-)

Some data sheet specify what thickness/distance was used in the D149 test. I looks like common gaps are 0.010", and 0.050" . There is a difference in results depending upon what gap is used. It's not like D877 (for liquid dielectrics) which specifies a 0.100" gap.

Cheers

Thank you very much for the copy. Seems I was correct in saying the method would not be clearly described and certainly not worth about $50.00 . It is not clear what gap to use; the table of some tests that included teflon at the top was nice !!VOLTS PER MIL!! but was incomplete in that the D149 rating was sorely lacking (as points of reference). What WAS clear is the "nagging" that the test specimen be dunked in (transformer?) oil - and thus the test may become moot and/or yield exaggerated results. And, naturally, there was umpteen references to other "standards" perhaps a hint to feed their infinite greed.

..and of course, the gap used is studiously NOT mentioned!