钟罩式气体流量标准装置内部容积的测量方法

基于尺寸测量法,测量了1000L钟罩内部的分阶容积。2个接触式长度计和旋转测量臂构成弦长测量机构。将罩体沿轴向划分为若干等间距截面,以15°采样间隔测量长度计与罩体内壁的接触点到测量臂旋转中心的距离,由接触点空间坐标确定各截面的轮廓。提出一种新的面积扫描法计算各层截面面积。经与圆度误差法的测量数据对比,当采样间隔密集时(5°或15°)2种方法的测量结果比较吻合。由各层截面面积及其轴向间距,计算得到分阶容积数据表作为罩体内部容积的标定结果。

A Method for Measurement of the Inner Volume of Bell Prover

The inner volume of a 1000L bell prover is measured by a new facility. A chord length measuring element is made up of two length gauges and a rotating arm. The whole volume of the bell is measured off 256 cross sections with axially equal spacing, and the spatial coordinates of the points, at which length gauges contact the bell’s inner wall,are obtained with a sampling interval of 15° to reproduce every section profile. A new sweep method is introduced to calculate the areas of section profiles. The comparison with the method for the assessment of departure from roundness shows that the results of the two methods coincide with each other when small sampling interval is adopted. A data sheet for all element volumes along bell axial is presented as calibration result.