LY311 Single Phase Multi-Function Standard Meter  is a new generation of multifunctional standard meter produced by our company, which adopts new hardware and software design, and can simultaneously measure single-phase voltage, current, frequency, phase, active power, reactive power, apparent power, active power, reactive power, and can measure high-order harmonic distortion (up to 64th harmonic) and the characteristics of the hardware gearshift of the small current, which makes the whole machine with a wider measuring range and wider application range. It has a wider measurement range and a wider application range.