... user interface DFM-2 Portable Three-phase Reference MeterI. IntroductionDFM-2 is suitable for three phase electrical energy meter testing equipments and ... component, power factor of all the phases, phase angle between voltage and current, phase angle between one voltage and another, active power ... .1%6. Accuracy of active electric energy: 0.02%7. Phase range:0°~359.9°, accuracy: 0.02%8. Frequency range ...