Frank, Thanks for the info. Do you have a link to the EEVblog discusison on this? If not, possibly some search terms to narrow it down (10VDC is too generic).
Joe Gray W5JG On Tue, Mar 8, 2016 at 4:47 PM, Frank Stellmach <[email protected]> wrote: > Hi Joe, > > yes, there has been a longer discussion on eevblog a few years ago.. > interesting explanations.. > > > Here's mine: > > Originally, the Weston Standard Cells had an odd value of 1.01865V. This was > transferred to other values by KV dividers. These dividers were easily built > in decades, but maybe that did not prefer 10V, yet. > > Analog meters at that time also had no preference, as they had several > overlapping ranges, sequenced like 1-3-10, or 1-2-5-10. > > When more precise DVMs with higher resolution were built in the 1960ties, > like the Fluke Differential DVMs, as for example the 883A, 893A, and so on, > they got decimal ranges, as a necessity for cascading. > HP also designed several standards and differential DVMs having 9.9999X as > F.S. > > Also, digital counters and early digital DVM, being based on such counters, > naturally had a F.S. like 9.999. > > You can often find in the catalogues of that era, that digital or > differential DVM with a F.S. of 11V or 12V were described as 10V instruments > with 10% or 20% of Overrange Capability, or so. > > So there was a necessity to have as a reference these Cardinal Points like > 100mV, 1V, 10V, 100V, 1kV, with 10V being the most stable and easiest one to > realize. > > And that lasts until today, although a direct calibration on the 6.9.. 7.2V > of zener elements like the LTZ1000 or LTFLU would be much more stable and > more precise than the 10V from a 732B. > > Frank > > > > > > _______________________________________________ > 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.
