17 Dec
2008
17 Dec
'08
10:59 a.m.
>>>> "Tony" == Tony Duell <ard
at p850ug1.demon.co.uk> writes:
> A DVM with a built-in standard cell?? Neat! Got
pics and/or
> schematics? I'd love to see that.
Tony> It was quite common at one time. The ones I've memtioned have
Tony> ther traditional H-shaped glass things in them...
Makes sense. A DVM needs an accurate reference. These days that's a
solid state device, the high end successor to the Zener diode. (I'm
not sure how they work -- quite possibly a completely different
scheme.)
Before that came out you'd need something else, and a Weston cell is
certainly a very good way to solve the problem.
paul