[Test-Equipment] Simple DC Voltage Standard?

[Jeff Furman]

I recall,

Confucious says, a man with two clocks never knows the correct time.

One thing standards labs have done, is circulate stable devices for each 
of them to measure. Everyone reports their measured values to the group.
A consensus of the probable value develops from this exercise.

This may be out of favor since absolute standards are available 
(Josephson junctions, etc.)

I don't recommend shipping standard cells, but solid state references can 
survive shipping.

Jeff AD6MX