GF312B portable three phase energy meter calibrator with printer is used to calibrate three phase, single phase, active and reactive energy meters error. And it also can be used as voltage, current and power meter to measure AC parameters of three phase power line. It can measure wave distortion factor and 2nd to 64nd harmonic wave. GF312B calibrator is used for grid corporation of measurement and energy test center, metrological service of power supply bureau, national energy measurement of testing authorities.