一种大口径电磁流量计的单位元标定方法  

Calibration Method for Large Electromagnetic Flowmeters Based on Unit Element

作　　者：李斌[1] 姜玉林[1,2] 孙向东 李雪菁[2] 

机构地区：[1]上海大学机电工程与自动化学院,上海200072 [2]九江学院电子工程学院,九江332005 [3]浙江迪元仪表有限公司,义乌322000

出　　处：《机械工程学报》2012年第20期27-32,共6页Journal of Mechanical Engineering

摘　　要：针对传统大口径电磁流量计实流标定成本高的问题,提出用小测量管作为单位元的低成本标定方法。以微元理论为基础,将整个流量计测量区域划分成若干个轴向子空间,用小测量管逐个测量各个子空间的感应电动势,提取其有效特性信息,重构后得到整个流量计空间的特性分布,有效解决实流标定带来的成本过高问题,为大口径电磁流量计的低成本标定提供一种有效的方法。重点对零点漂移下小测量管的感应电动势、装置系数和仪表系数的关系进行研究分析,并给出标定系数的最终表达式。用实流标定法和单位元标定法进行简单的标定比对试验,结果表明单位元标定法的准确度等级为0.5级,具有一定的可行性。The real flow calibration cost of large diameter electromagnetic flowmeter is very high, in order to solve the problem, a new low cost calibration method is presented, which take small tube as unit element. It divides the flowmeter measurement zone into several axial subspace based on element theory, the induction electromagnetic force of each subspace was measured with a small measure tube, and the effective information of characteristic is extracted, then the characteristics distribution of flow meter is reconstructed with them, it effectively solves the high cost of real flow calibration, which provides an effective method for the low cost calibration of large diameter electromagnetic flowmeter. The induced electromotive force under zero drift, and the relationship between device coefficient and instrument coefficient of small measurement tube are focus discussed, and the final expression of calibration coefficient was given. A large diameter electromagnetic flowmeter was calibrated with actual flow calibration and unit element calibration, respectively. Experimental results indicate that the new calibrating method is available, and the accuracy grade is 0.5.

关 键 词：大口径 电磁流量计 低成本标定 单位元 

分 类 号：TH814[机械工程—仪器科学与技术]