Sorry, no history at all. They were salvaged from old equipment. From what I read, they are already below their voltage threshold and should be tossed. I just thought it would be interesting to measure them anyway.
I think the decline rate was supposed to be around 0.08 uV per year, or something like that. After the 3457A is calibrated, I will try to track these three cells, even though they are supposed to be no longer stable. It will be an interesting exercise and will only cost me a bit of time. If the cells prove to be unstable, I can always toss them later. I certainly won't be using them as any type of standard. I already acquired a Fluke 845A. It needs some attention, but seems to mostly work. Joe Gray W5JG On Mon, Aug 26, 2013 at 9:10 PM, J. L. Trantham <jlt...@att.net> wrote: > Joe, > > Do you have any data about prior measurements of these cells or their > history? > > I read somewhere there is a predicted decline rate based on time and > temperature IIRC. > > Once you get the meter calibrated, you can 'track' their measurements. > > Might also be time for a 'differential voltmeter' to add to the 'stable'. > > Joe > > -----Original Message----- > From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On > Behalf Of Joseph Gray > Sent: Monday, August 26, 2013 9:59 PM > To: Discussion of precise voltage measurement > Subject: [volt-nuts] Old Weston cells > > I got my hands on a few very old, unsaturated cells. I figured that they > would be no good after all this time. Just out of curiosity, I measured > them > on my 3457A, which hasn't been sent off for calibration yet. > > DMM was set to 3 V scale to keep the input impedance high. Room temperature > = 26 C. > > Cell #1 = 1.018288 > Cell #2 = 1.018236 > Cell #3 = 1.018224 > > I read that when they get below 1.0183 V, they are no good. Is there any > (easy) way to rejuvenate these cells? > > Joe Gray > W5JG > _______________________________________________ > 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.