flow used under normal conditions should be estimated first, and then the water meter of the specification closest to the value of the normally used flow should be selected as the first choice.TECHNICAL TERMQ1(Min. Flow Rate L/h): The indication value of the water meter is required to conform to the minimum flow rate of the maximum allowable error.Q2 (Transitional flow rate L/h)): Between the commonly used flow Q3 and the minimum flow Q1, the flow range is divided into two regions, "high zone"