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对三种天然气压缩因子计算方法：经典热力学法、SGERG-88法、SY／T6143—1996法进行了介绍并对计算结果进行了对比，第一种方法的计算精度远不能满足贸易结算的要求，我国现行的第二种计算方法与ISO标准方法相比，在10℃以上的温度范围内基本相符，但在10℃以下的低温段则偏差较大。由此说明，我国目前所实施的计量标准与国际上认可的ISO标准方法之间有较大的偏差；同时，对不需要在线计算的场合，提出了一套基于数据拟合的计算体积修正系数的高精度近似方法，可提高体积计量仪表的性价比。

Calculation of Natural Gas Compression Factor and Volume Measurement

??The article introduces 3 calculating methods for the compression factor of natural gas,i.e.traditional thermodynamic method,SGERG88 method,and SY/T 6413-1996 method,and compares their results.The calculating accuracy from the traditional thermodynamic method can hardly meet the requirement of trade measurement.Comparing the method SY/T6143-1996 currently used in China with ISO method,they are coincident when temperature is above 10??.,but they are much different when temperature is below 10??.So,it means there is big difference between the current national standard and ISO standard.Aiming to the situation when on line calculation is unnecessary,the article proposes an approximation method with high accuracy to calculate the volume correction coefficient based on data fitting,which can improve the performance/price ratio of gas volume gauge.