具有零漂容忍度和非线性校正功能的电磁流量计仪表系数计算方法  

Calculation Method of Electromagnetic Flowmeter Coefficient with Zero-drift Tolerance and Nonlinear Correction Functions

作　　者：汪春畅 许伟[1] 徐科军[1] 吴建平[1] 梁利平[1] 

机构地区：[1]合肥工业大学电气与自动化工程学院

出　　处：《化工自动化及仪表》2017年第9期837-840,877,共5页Control and Instruments in Chemical Industry

摘　　要：针对部分国产电磁流量计通过了出厂标定,但再次校验时误差超差的问题,进行了大量实验研究。确定造成小流速点超差的原因为仪表的零点漂移和非线性特性。分析了目前常用的几种计算仪表系数方法存在的问题,提出分段线性拟合仪表系数计算方法。该方法同时兼顾小流量点和大流量点的误差,为仪表的可能零点漂移预留较大的空间,克服仪表的非线性特性,使电磁流量计再次校验或应用时都能满足测量准确度的要求。Aiming at some domestically-made electromagnetic flowmeters which passing ex-works calibration but troubled by the error which exceeding the specified range in re-examination,numbers of experimental studies were performed to show that,both zero-drift and nonlinear characteristics of the meter can result in this error at a small flow rate. Through analyzing the existing calculation methods for the instrument coefficient,a piecewise linear fitting method was proposed which having the errors at small and large flow rates taken into account to reserve a large space for the zero drift and to overcome the nonlinear characteristics. This makes the electromagnetic flow-meter satisfy accuracy measurement when they are re-examined or applied.

关 键 词：电磁流量计 超差 零点漂移 非线性 仪表系数 分段线性拟合 

分 类 号：TH814.93[机械工程—仪器科学与技术]