本文件提供了通过测量或计算确定天然气能量的方法，并描述了需要采取的相关技术和措施。热能的计算基于对所传输气体的质量或体积的单独测量及其测量或计算的热值。给出了计算不确定性的一般方法。 仅描述了当前使用的系统。 注:在商业或官方贸易中使用此类系统可能需要国家授权机构的批准，并且需要遵守法律法规。 本文件适用于从家用到超大型高压输送的任何气体测量站。 新技术不排除在外，前提是其经验证的性能等同于或优于本文件中提及的那些技术。 气体测量系统不是本文件的主题。

This document provides the means for energy determination of natural gas by measurement or by calculation, and describes the related techniques and measures that are necessary to take. The calculation of thermal energy is based on the separate measurement of the quantity, either by mass or by volume, of gas transferred and its measured or calculated calorific value. The general means of calculating uncertainties are also given. Only systems currently in use are described. NOTE Use of such systems in commercial or official trade can require the approval of national authorization agencies, and compliance with legal regulations is required. This document applies to any gas-measuring station from domestic to very large high-pressure transmission. New techniques are not excluded, provided their proven performance is equivalent to, or better than, that of those techniques referred to in this document. Gas-measuring systems are not the subject of this document.