On Dec 17, 2008, at 2:13 PM, Chuck Guzis wrote:
It was quite
common at one time. The ones I've memtioned have ther
traditional H-shaped glass things in them (the Blackburn vavled
one has a
pair of them, just bare glass, on a bracket, the Solartron ones
have them
encased in a little plastic housing). I have a later DVM which has an
enacpsulated thing with 2 wires comiong out that appears to be a
standard
cell, certainly the voltage between said wires, measured on a
high-impedance votlmeter, is about right.
One of the "round-tuit" jobs when I was an instrumentation tech was
replacing all of those Weston-cell-plus-dry cell-plus-calibration-
slidewire setups with Honeywell constand-voltage supplies, even in
L&N equipment. You'd strip out the entire reference-voltage section
and drill and tap a couple of holes in the instrument frame and mount
the supply and connect up the wires (including AC). Took about 45
minutes to do right and you never had to replace another battery in
that instrument. I must have done 100 of those conversions.
Yow...What was the application? I'm familiar with those Honeywell
CV supplies; they're nowhere near as stable as a Weston cell. Far,
far, FAR more rugged though, and resilient to temperature
shifts...which Weston cells are not.
-Dave
--
Dave McGuire
Port Charlotte, FL