Re: [volt-nuts] Short term "standard" cell?
How do silver oxide cells compare to mercury cells for voltage stability? When I last looked into this, I concluded that there were two different silver oxide chemistries with a slight variation in voltage between them. On Sat, 11 Mar 2017 09:21:02 -0800, you wrote: >Hi Chris: > >I think it was my Heathkit VTVM that said to get a fresh AA battery and use it >as a 1.52 Volt standard to calibrate the >meter. An even better way was to use a Mercury coin cell since they were 1.35 >volts and very stable. They were used for >light meters and voltage references because of the very flat discharge curve. > >But when you are looking for many more digits of accuracy/precision then a >battery may not be the best choice since >pretty much everything will cause a variation. Maybe in order of importance: >temperature, atmospheric pressure, >humidity, impedance of measuring equipment, > >There are a few low cost voltage standards available where the maker has an HP >3458. For example by Geller and Malone: >http://www.prc68.com/I/MTE.shtml#DCVR > >The care and feeding of chemical standard cells is such a pain and they are >inferior to the modern electronic standards >so they have become obsolete. The label on my Eppley shows 5 digits (4 >printed and the last hand written). Note since >there's liquid involved there is also an "Up" direction. >http://www.prc68.com/I/Eppley.html#Standard_Cell > >http://www.prc68.com/I/Fluke332B.html ___ 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.
Re: [volt-nuts] Short term "standard" cell?
Hi Chris: I think it was my Heathkit VTVM that said to get a fresh AA battery and use it as a 1.52 Volt standard to calibrate the meter. An even better way was to use a Mercury coin cell since they were 1.35 volts and very stable. They were used for light meters and voltage references because of the very flat discharge curve. But when you are looking for many more digits of accuracy/precision then a battery may not be the best choice since pretty much everything will cause a variation. Maybe in order of importance: temperature, atmospheric pressure, humidity, impedance of measuring equipment, There are a few low cost voltage standards available where the maker has an HP 3458. For example by Geller and Malone: http://www.prc68.com/I/MTE.shtml#DCVR The care and feeding of chemical standard cells is such a pain and they are inferior to the modern electronic standards so they have become obsolete. The label on my Eppley shows 5 digits (4 printed and the last hand written). Note since there's liquid involved there is also an "Up" direction. http://www.prc68.com/I/Eppley.html#Standard_Cell http://www.prc68.com/I/Fluke332B.html -- Have Fun, Brooke Clarke, N6GCE http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Original Message In preparation of (hopefully!) Getting that fluke 332A running and sticker shock of what the 732A and similar references go for, I wonder about normal, every day alkaline or lithium batteries and their short term stability. Here's the half baked idea. A fresh, standard 1.5V, or 3V lithium, alkaline, or silver oxide button cell battery, or even an AA sized cell, measured by someone/some place with a known accurate precision meter. Invisioning 6 or so decimal places. Could that cell then be shipped, and used as a reference in another altitude? I haven't spent a ton of time looking, but haven't yet found anything on the web about stability of these types of batteries. Regards, Chris Sent from my SMRTphone ___ 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] Short term "standard" cell?
In preparation of (hopefully!) Getting that fluke 332A running and sticker shock of what the 732A and similar references go for, I wonder about normal, every day alkaline or lithium batteries and their short term stability. Here's the half baked idea. A fresh, standard 1.5V, or 3V lithium, alkaline, or silver oxide button cell battery, or even an AA sized cell, measured by someone/some place with a known accurate precision meter. Invisioning 6 or so decimal places. Could that cell then be shipped, and used as a reference in another altitude? I haven't spent a ton of time looking, but haven't yet found anything on the web about stability of these types of batteries. Regards, Chris Sent from my SMRTphone ___ 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.
