For all of the instruments I referenced, including the Fluke 8508A by inference of the Fluke short model number, it is much more about controlling or minimizing Seebeck EMF. For the low end resistance ranges on these instruments, far greater error is introduced from thermal EMF than from the absolute trace resistance of the board. That said, the 8508A-7000K board has thick, wide traces on BOTH sides for the current and sense terminals and a smaller trace bridging sense to current. A more compelling test might be to measure and record sub-microvolts changes over time with air currents on the terminals. If this test was repeated using the solid copper S-shaped 4W short suggested for the 3458A calibration, I would guess that the solid wire might take more time to come to thermal equilibrium with the terminals. I may give it a try. Don
-----Original Message----- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Jeremy Nichols Sent: Saturday, November 11, 2017 12:52 PM To: Discussion of precise voltage measurement <volt-nuts@febo.com> Subject: Re: [volt-nuts] Banana jack shorting straps It would be interesting to see results of a resistance measurement of some of these "shorts" using an appropriate low-resistance instrument. Jeremy N6WFO On Sat, Nov 11, 2017 at 8:09 AM Don@True-Cal <truecalservi...@gmail.com> wrote: > Mark, > I would recommend duplicating the Fluke 8508A-7000K 4W Short > Calibration Board design. This board fits my 3458A & 3457A exactly and > drops in place nicely from the top after the binding posts are opened > sufficiently. I also have the banana plug style 2001-182-01B Cal Short > that fits my Keithley > 2002 > (also 2000/01/15). I can provide hi-res pictures of either one and > provide measurements if needed. Both styles have Ag plating. See attachment > left. > Don > > -----Original Message----- > From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Mark > Sims > Sent: Thursday, November 09, 2017 7:01 PM > To: volt-nuts@febo.com > Subject: [volt-nuts] Banana jack shorting straps > > Here's what they should look like... dots are via stitching between > the top and bottom. > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. -- Sent from my iPad 4. _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
