Knowing my fondness for old test equipment, a friend has given me a Leeds & Northrup lab-grade potentiometer. I'm trying to find out more about it, but the model plate is missing. Other than that, it's in beautiful shape.
The left side of the unit is the galvanometer. Just to the right of the galvanometer section are two rotary controls. The upper one is a pot used to enter the voltage of the internal standard cell, and the lower one is a rotary switch labeled MILLIVOLTS and the knob has dual markings for 0-75 or 0-15. To the right of these knobs is the main slidewire with a dual scale ( 0-5.5 mV and 0-1.1 mV). Toward the right side is the reference junction slidewire, again with dual scales (0-5.0 mV and 0-1.0 mV). On the right side of the wooden case are two brask disks labeled COARSE and FINE that are attached to pots in series with the internal battery (not the standard cell).
Can anyone offer suggestions as to the L&N model number for this device? I'm particularly interested in the use and setting of the FINE and COARSE controls on the side of the case. It came with a couple of thermocouples, but I haven't tried measuring any temperatures yet.
Regards, Ed Bailen