标准表法流量计算及不确定度评估分析

以圆柱齿轮流量计做为标准流量计为例,介绍了在标准表法流量标准装置中非定点使用的标准流量计的几种典型流量计算方法,并给出各种流量算法引入的不确定度评定方法。实例对比表明,采用最小二乘法拟合计算,选择与流量计自身特性匹配的拟合阶次可有效降低算法引入的不确定度;选用流量修正值计算流量,对于低流量区域算法引入的相对不确定度较大;采用仪表系数和流量修正系数计算流量引入的不确定度比较接近。

Master Meter Method Flow Calculation and Uncertainty Evaluation

Taking the cylindrical gear meter that is used as master flow meter as an example, several typical flow calculation methods for the master flow meter used in the non-fixed point in the standard flow facility by master meter are introduced, and the uncertainty of each flow calculation method is evaluated. The comparison of the examples shows that using the least squares fitting calculation and selecting the fitting order matching the characteristics of the flowmeter can reduce the uncertainty introduced by the algorithm obviously, the method of selecting the flowrate correction value to calculate the flow rate is relatively inefficient for the low flow range, and the uncertainty introduced by using the meter factor is relatively close with that introduced by using the flow rate correction coefficient.