... three-phase meter takes single chip as kernel, adopts three separate voltage channels and current channels. DF-301 three-phase meter takes single chip as kernel, adopts three ... seven functions: voltmeter, ammeter, phase meter, phase sequence meter, frequency counter, power meter, power factor meter.2. Display vector figures with ... ': aBigImageSrc } ); } )(); Hot Sale! DF-301 Portable Three-Phase Meter