Help identifying old lab equipment

[tcraig]

Hi all,

Does anyone know what this is? It was in my late father's lab/shop. He was a professor of physical chemistry at the University of Pittsburgh specializing in building lab equipment, especially electronics. He retired in 1989. I suspect this item dates back to the 60's. I have no idea what it is or what to do with it.

Thanks,
Tom Craig
[email removed for privacy]

 

[danadak]

Precision resistor substitution box ?


Regards, Dana.

 

[Delta Prime]

Here's another resistor substitution box sold for pretty penny. Yours is far Superior I would take that to auction. I don't mean to come off as insensitive to your loss... apologies.

 

[73's de Edd]

All . . . . .
I lean towards a HEAVY perception of it being a precision adjustable bridge.
Look at the extreme top left terminal screws . . . . . the BA aspect has a polarity designation.
Techno-gibberish assignments for the next 12 terminals then + and - terminals for a GA lvenometers external collection, then an external Leeds precision reference cell hook up and its required polarity designations.
3 more sets of unfamiliar connections . . . BUT . . . with their polarity criticality being shown.
If being a bridge, then the next two (Z?) terminals set down on right top corner, I would want to see as being for the tested resistor in the case of a bridge, with the 9 bottom left corner decade resistors being the adjustable aspects of the 3 variables of a bridge . . . . in comparing to that resistor being tested.
Small GA knob right bottom corner, being an adjustable shunt resistor across the Galvanometer, so as to initially desensitize until the bridge is closer to zero balance, where meter sensitivity can then be increased by then incorporating less shunting resistance.
Can't make out the knob markings on the 4 larger = 2 smaller knobs in the right top corner area.
How about looking up the potential grandson of this unit as being the Leeds &Northrup K3 unit with more built in aspects.

 

[AnalogKid]

Construction suggests a vintage one or two decades older, like pre/post WWII. Could be a precision adjustable resistor peripheral for an analog computer.

ak

 

[hevans1944]

I have something very similar. It believe it is a precision Wheatstone Bridge. The standard cell is used to adjust the current in the bridge by nulling the voltage drop against the standard cell voltage. I keep mine around to remind me of the vast history our hobby enjoys. The wooden case polishes up nicely, too.