GF211 double clamp phase volt-ampere meter is a multi-functional portable instrument. It can measure not only alternating voltage, but also alternating current. Its important function is to measure phase angle between two voltages, between two current or between voltage and current. The current signal is obtained by the clamp current transformer without cutting off current wire. It can discern inductive circuit and capacitive circuit; can directly read differential protection phase among every unit of CT; can check connection of transformer; measure three way voltage phase sequence; can check whether the meter connection is right or not; can evaluate the running speed of electric kWh meter. It has high resolution of current, so can be used as a leakage current meter. It is an ideal choice for electric power bureau, factories, mine, petroleum -chemistry enterprises, metallurgy factories and so on