... maintenance, it is an ideal calibrating equipment for meter makers.2 Main Feature2.1. Digital frequency modulation, phase modulation, ... modulation. Intelligently designed, operation is controlled by the keyboard;2.2. Voltage output with permanent voltage, current output with permanent ... 1%;3.10. Output voltage, current, power stability 0.02%/2(minutes);3.11. Output voltage, current accuracy 0.1%;3 ...