GF112D is a single-phase handheld electronic meter test unit in accuracy class 0.1or 0.2, used for testing single phase electricity meters error on site. Wide measurement range from 1mA to 120A and 0 to 300V, and also can be used to test alternating current parameters - voltage, current, active power, reactive power, apparent power, harmonics, phase angle, power factor, frequency, energy etc.