Hi Tom, On Jun 17, 2013, at 2:48 PM, "Tom Miller" <[email protected]> wrote:
> > ----- Original Message ----- From: "Steve Byan" <[email protected]> > Subject: [volt-nuts] Semi-precision high resistance measurement > >> Any ideas as to what's going on? How can I improve my measurement procedure >> to get repeatable results? Do I really need better climate control even at >> the 3 1/2 or 4 1/2 digit level of precision? What's with the polarity >> sensitivity of the 8050A resistance measurements? Suggestions and advice >> would be gratefully accepted. > > On the high value resistors, did you clean them well with 99% dry isopropyl > alcohol (or maybe acetone) after you handled them? The oils on your skin are > very conductive when measuring in the high megohm region. They are still installed on the range switch. I did think about surface contamination and did clean them with anhydrous isopropyl, but I can't clean them that well without removing them from the range switch. I probably did clean most of the surface that's been handled during my disassembly of the instrument. Would the resistance of those oils be polarity sensitive? I should check other high-value resistors, but I don't have much if anything handy that's over 1 megohm. I'll have to hunt around the shop and see what I can turn up. Best regards, -Steve -- Steve Byan <[email protected]> Littleton, MA 01460 _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
