测量气体活塞式压力计有效面积时气柱差的误差分析

Error Analysis of Gas Column Difference during Measuring Effective Area of Gas Piston Gauge

目前多采用起始平衡法测量气体活塞有效面积,起始平衡法是用一定的小砝码来消除两活塞参考面液(气)体的高度差所产生的压力。即认为液(气)柱所产生的压力是不变的。但由于气体的可压缩性,气体密度随压力变化而变化,这就造成了气柱高度虽然不变,而气柱所产生的压力却是变化的,从而产生测量误差。本文就此问题进行分析,力求使气体活塞式压力计的量值传递更准确。

At present, the effective area of the piston gauge is mostly measured with the initial balance method. This method uses the definite small mass to eliminate the pressure caused by the difference of the liquid （gas） of the two reference plans of the piston gauge. That means the pressure caused by the liquid （gas） column is invariable. But owing to the compressibiliy of the gas, the density of the gas is changing with the change of the pressure. Even though the heigh of the gas column is invariable, but the pressure caused by the gas column is changeable. That creates the error of measurement. This paper analyses this problem for making effort to transmit the pressure value of gas piston gauge more exactly.