Since R is quite tied to E, i found this paper to be quite interesting ... Pettis was also the resistor expert who worked with Bob Pease in his last project trying to push the state of the art at the time for special resistors needed on the project. The invention of Evanohm ....
http://www.edn.com/design/analog/4427151/The-last-half-century--Wirewound-resistors-Part-one http://www.edn.com/design/analog/4427940/1/The-last-half-century--Wirewound-resistors-Part-two On Thu, Aug 6, 2015 at 1:44 PM, Richard Moore <[email protected]> wrote: > Check with Edwin Pettis at Ultrohm in Grand Junction, Co. H ewinds superb > ww resistors using Evanohm wire with tempcos under 3ppm/degC, with 0.01% > tolerance for around $14 each. I’ve bought some and have been extremely > pleased. Don’t know the largest he can make or at what price… > > [email protected] > > Dick Moore > > > > Message: 1 > > Date: Thu, 6 Aug 2015 16:25:54 +0100 > > From: "David C. Partridge" <[email protected]> > > To: "'Discussion of precise voltage measurement'" <[email protected]> > > Subject: [volt-nuts] Precision resistors > > Message-ID: <5D9EFA13BAB94DCA901607C1EDEA4911@APOLLO> > > Content-Type: text/plain; charset="UTF-8" > > > > Looking for a set of precision resistors for calibration purposes. > > > > I need the following values to calibrate the ohms ranges on my meters: > > > > 100 > > 1k > > 2k > > 10k > > 20k > > 100k > > 200k > > 1M > > 2M > > 10M > > 20M > > > > The crucial factor isn't that they be *exactly* the values above, so I > don't necessarily need 0.001% parts. Low TCR is important, and I will need > to know that actual values to 10ppm or better. > > > > I'm looking for suggestions on the best choice of parts and pricing? I > believe the Vishay HZ series may fit the bill for the lower values but they > may be rather expensive. > > > > Regards, > > David Partridge > > _______________________________________________ > 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. > _______________________________________________ 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.
