A new test board for portable watt-hour meter standards

THE Central Laboratory of the New England Power Service Company maintains the watt-hour standards for the New England Electric System. Until very recently, the methods and equipment used were similar to those found in many utility laboratories. Primary standards were standard cells, which, through potentiometers, volt boxes and shunts, established the calibration of laboratory standard wattmeters. The wattmeters, in turn, served as transfer instruments from d-c reference to a-c working values. A good-grade pendulum clock served as time standard.