A vintage Weston, Model 1, direct-current voltmeter. The Model 1 was developed by Edwin Weston in 1888 and served for many years as a prime standard for laboratories. The particular unit (serial number 55180), which measures 17 cm in width and 15 cm in height, was manufactured and calibrated in 1946. It was used in the Nuclear Physics Branch at CRNL. It had internal shunts to allow full-scale usage for 3, 15, or 150 volts dc. The calibration sheet is attached to the reverse of the unit.
