The SHDFR_PQ (Online Power Quality Monitoring Device) is a high-precision device specifically for monitoring power quality online. It has such functions as high-precision monitoring of power quality steady state indices, recording of transient power quality events, real-time measurement and monitoring of the power and quantity of electricity, recording of power quality events, pass-rate statistics, comprehensive analysis of monitoring data for power quality problems, report statistics and output. With these powerful functions, the device meets the requirements of various likely power quality monitoring scenarios.