Design of a Flow Automatic Calibration System Based on The Master Meter And Dynamic Weighing Methods

Flow measurement technology is an important part of metrology, in which the flow calibration facility used to measure the accuracy of water meters has become the research focus of most institutes of metrology. In order to solve the problem of measurement error of ultrasonic water meter due to various interfering factors in the flow calibration process, this paper designs a set of ultrasonic water meter flow calibration system with high degree of automation and intelligence. Firstly, by analyzing and studying the working principle of the water flow calibration device, and according to the actual flow calibration range, the calibration method combining the master meter method and the dynamic weighing method is determined. And then, in order to improve the automation degree of the flow calibration system, the flow calibration control algorithm is analyzed and designed in detail. The algorithms include the overall control algorithm, the control algorithm of the master meter method and the control algorithm of the dynamic weighing method. Finally, a flow correction algorithm based on linear interpolation was designed and calibrated using this algorithm. Test data show that after the flow correction ultrasonic water meter value error in the "high area" are not more than 2%, in the "low area" is not more than 3%, and the repeatability is less than 0.05%. Compared with manual calibration, the flow calibration system designed in this paper realizes the high-precision automated flow calibration of ultrasonic water meters, which greatly improves the detection efficiency and accuracy.