Description

Metal box with a hinged lid that opens to reveal an instrument panel. The panel has four dials and five terminal lugs, as well a found face covered in glass with a dial with a scale graduated from 50-0-50. A scale indicator is below the scale. A paper pasted on the inside of the lid has operating instructions. Serial number J-57480.

This instrument is an electrical resistance strain gage and measures physical variables like force, pressure, torque, vibration, displacement, and (of course), strain.