In the past glow discharge lamps were widely used as reference voltage sources, it would be interesting to compare them with modern semiconductor zener diodes. Has anyone had experience using them?
I've had a Solartron LM1420 voltmeter, but I have now sold it so I can't do any serious tests.
It used a neon as the secondary reference, with an internal unsaturated Weston standard cell (still in spec, unexpectedly) as the primary reference. My characterisation based on
playing around a
little bit: the neon voltage was unpredictable, but once the reading was adjusted against the Weston it was stable enough for a 3.5 digit DVM. By that I mean after a week being turned off in a domestic environment, the reading did not need re-adjustment.