中大口径电磁流量计无液校准技术的应用研究

基于电磁流量计测量原理,在建立了包含相关物理量的微分方程及边界条件基础上,提出了一种电磁流量计无液校准技术,设计了一套无液校准设备。采用逐点测量管壁磁感应强度及测量传感器结构尺寸的方法,获得确定的边界条件,用数值方法求解微分方程,获得传感器的灵敏度系数,并对2台口径200 mm电磁流量计进行了无液和实流的对比试验,两者所获得的灵敏度系数相对误差不超过0.5%。

Study of No-liquid Calibration Technique for the Medium-and-large Diameter Electromagnetic Flowmeter

A no-liquid calibration technique for electromagnetic flowmeter (EMF) is presented. The proposed method utilizes the electromagnetic measuring principle. Several differential equations for the relevant physical quantities and corresponding boundary conditions are established. A set of no-liquid calibration equipment is designed and implemented. By measuring the point-by-point magnetic induction on the boundary surface as well as the structure dimensions of EMF, the sensitivity of EMF are acquired via the numerical solution of the differential equations with measured boundary conditions. The comparison of the no-liquid and practical-flow calibration methods is carried out on two EMFs with diameter of 200mm. The relative error of the sensitivity data determined by the two methods is less than 0.5%.