Maybe I can ask on 4HV.org ? ________________________________________ From: volt-nuts <volt-nuts-boun...@febo.com> on behalf of David C. Partridge <david.partri...@perdrix.co.uk> Sent: 15 January 2018 03:22 To: 'Discussion of precise voltage measurement' Subject: Re: [volt-nuts] Any list members in UK who can accurately characterise a 732A and a 10K resistor
Guildline 9330 nominal accuracy 2.5ppm. -----Original Message----- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Dr. David Kirkby Sent: 14 January 2018 23:03 To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] Any list members in UK who can accurately characterise a 732A and a 10K resistor On 14 January 2018 at 15:40, David C. Partridge < david.partri...@perdrix.co.uk> wrote: > I've recently rebuilt a 732A and it seems stable, but what I don't > know is its actual output voltage down to the last ppm > > I've also acquired a Guildline 3330 10K standard resistor but again > don't know its value - my 3458A says it is 10,000.43 ohms which I find > rather hard to believe (way out of spec.). > Is there a tight spec on the nominal value? I can't find the specification on those from a Google search, but I thought the actual value was not very well controlled, but the stability is. So the fact it is 0.43 Ohms high, may not mean it is out of spec. I would imagine there's a trade-off between getting the initial value correct and the stability. If you design the resistor for maximum stability, you may not be able to simultaneously get the value close to its nominal value. It you do things to get the nominal value better, they may degrade the stability. > > I know someone with a recently calibrated 3458A (Keysight Calibration, > not accredited, not Loveland), but can anyone do better? I'd prefer > not to have a pay for a formal cal lab report on these. > A non-accredited Keysight calibration should be no less accurate than an accredited Keysight calibration. From what I understand, the procedure is the same, but you just get a few extra words on the cal certificate if it is accredited - and pay quite a bit more. It costs Keysight money to be accredited, so they pass the costs of that onto people that need an accredited cal certificate. I wonder what ones chances of going to NPL on their open-day (17 May 2018) and getting a measurement performed as a favor? If you don't want an official cal certificate, but just a number you scribble on a bit of paper, you might be able to get it done free of charge. I know the lab with a primary voltage standard (Josephine Junction), was open to the public on the last open-day, which was in 2016. I don't think there was any lab open that measured resistors though. > Thanks > Dave > Dave _______________________________________________ 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. _______________________________________________ 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.
