The model GF111D high precision DC reference energy meter are used in electric power, metrology, military industry, manufacturing and scientific research institutes and other DC measurement fields or laboratories. Characteristic features of the GF111D are its wide measuring range, high accuracy and high tolerance to unwanted external influences. Its voltage range from 0 to 1200V, current range from 0 to 600A, DC reference standard of accuracy 0.02%. The DC reference standard offers high functionality combined with an excellent menu guided operation via built-in keyboards and colored 8 inch color touch LCD-display. It can automatically test DC energy meter error, energy accumulation , error of time of day.