Hi: When I was building automatic test systems we already had an HP 3458 in a system and when the second system was built the new 3458 had a front panel sticker (AFAICR it was green) with something about the "new volt". We checked them against a Fluke DC standard, not that the standard was that good, but so that we could see the difference in readings. The difference exactly matched the change in the definition. What difference would you see measuring say 10.0 Volts? Could the Fluke 332B be that instrument used then? This one looks very much like the standard we used. http://www.prc68.com/I/Fluke332B.html -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html The lesser of evils is still evil.