The phase voltmeter is a high-precision, low-cost, handheld, dual-channel input measuring instrument specially designed for on-site measurement of voltage, current, and phase. With this instrument, it is very convenient to measure the phase between U-U, I-I, and U-I on site, distinguish inductive and capacitive circuits and the phase sequence of three-phase voltage, detect the connection group of transformers, test secondary circuits and bus differential protection systems, read the phase relationship between CTs of each group in differential protection, and verify the correctness of wiring in electric energy meters. The input current is measured by using clamp-type current transformer conversion method, and the two input circuits are completely insulated and isolated, thus completely avoiding possible mis-wiring that could cause short circuits in the measured circuit or even damage the measuring instrument. The display uses a high-contrast liquid crystal display with a character height of 25mm, and the screen angle can be freely adjusted about 70° to achieve the best visual effect. : Phase meter, double-clamp phase meter, double-clamp phase voltmeter, clamp-type phase meter, clamp-type phase voltmeter, digital double-clamp phase meter, low-voltage volt-ampere phase detector, handheld digital double-clamp phase voltmeter, double-clamp digital phase meter, double-clamp digital phase meter, double-clamp volt-ampere phase meter, double-clamp volt-ampere phase meter, digital display double-clamp phase meter, phase voltmeter 1. Withstand voltage: between the voltage input terminal and the shell, between the iron core of the clamp-type current transformer (current clamp) and the clamp handle and the secondary winding wire Hz, between the two voltage input terminals can withstand a sinusoidal alternating voltage of 500V/50Hz for 1min test 2. Insulation resistance: between the circuit of the digital double-clamp phase voltmeter and the shell, between the two voltage input terminals: ≥10MΩ Enterprise products strictly follow international, national standards and industry regulations for production, and have passed the testing of national, provincial, and municipal electric power research institutes, metering centers, and major electric power authorities. All have passed ISO9001 international quality management system certification, the People's Republic of China metering instrument manufacturing license, GB/T19001-2016 quality management system requirements, GB/T24001-2016 environmental management system requirements, customer cases, and GB/T45001-2020 occupational health and safety management system requirements.