A new device for calibrating watt-hour meters

A NEW device has been developed to provide a better means of calibrating watt-hour meters, particularly in the field. With this device, the field testing of watt-hour meters is made much faster and easier as compared to the conventional methods of counting and timing of disk revolutions because an instantaneous and continuous visual indication of meter accuracy is obtained. In general, closer adjustment to correct registration is obtained than by the methods involving successive trials. The device is portable. No special disks, disk markings, or the like are required.