I'm not too well versed in this 1950's bakelite lab equipment stuff!
Maybe somebody can help me out figuring out how to run it?


I picked up this BEAUTIFUL Honeywell-Rubicon 2730 "potentiometer".
It's a lot more than a standard pot!

It has a fancy dial calibrated from zero to 75 millivolts, a Eppley standard
cell inside, several other controls cryptically labeled "R" and "C", plus a
few push buttons with unhelpful labels like "SO", "A", "B", "C".

Oh and it has this optical scale galvanometer that once started, will swing
for almost a minute before it settles down to a reading.

-- and -- it has this less than beautiful faux-woodgrain formica case.
I guess wood was out of style that decade.

Any ideas how one would operate such a device?

Probably a wheatstone bridge-- but what buttons do you push??

Regards,


George

On Mon, 4 Aug 2003 15:04:21 -0500, "George R. Gonzalez"
wrote:


I'm not too well versed in this 1950's bakelite lab equipment stuff!
Maybe somebody can help me out figuring out how to run it?


I picked up this BEAUTIFUL Honeywell-Rubicon 2730 "potentiometer".
It's a lot more than a standard pot!

It has a fancy dial calibrated from zero to 75 millivolts, a Eppley standard
cell inside, several other controls cryptically labeled "R" and "C", plus a
few push buttons with unhelpful labels like "SO", "A", "B", "C".

Oh and it has this optical scale galvanometer that once started, will swing
for almost a minute before it settles down to a reading.

-- and -- it has this less than beautiful faux-woodgrain formica case.
I guess wood was out of style that decade.

Any ideas how one would operate such a device?

Probably a wheatstone bridge-- but what buttons do you push??

Regards,


George



This is a device for measuring voltage by comparison with a standard
(the internal Eppley standard cell)., Honeywell-Rubicon and Leeds &
Northrup each made many different models.

There are different versions with varying accuracy... generally three
to five digits. The idea is to adjust the dials for null, then read
the voltage from the dials. You really need the manual for the
individual model, as there were many variations on the same theme.

BTW, these are very low-current devices. The standard cell cannot
supply any significant current, and the galvonometer is extremely
sensitive, in the microamp or perhaps nanoamp range.

The same is true for standard resistors. Normal maximum dissipation
for a standard resistor is 1/100 watt or less. This applies to the
resistors in your potentiometer.


73 de Leigh W3NLB