1.1 本规程涵盖了通过成分分析计算天然气混合物在基本条件（14.696 psia和60°F（15.55°C））下的热值、相对密度和压缩系数的程序。 2. 1.2 本规程适用于所有常见类型的公用事业气体燃料，例如，干天然气、重整气、油气（包括高和低Btu）、丙烷空气、汽化水煤气、焦炉煤气和干馏煤气，适用的分析方法如第节所述 6. 可用。给出了其他基本条件的计算程序。 1.3 单位-- 以英寸磅为单位的数值应视为标准。括号中给出的值是国际单位制的数学转换，仅供参考，不被视为标准。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 热值是衡量纯气体或气体混合物用作燃料的适宜性的指标；它表示通过燃烧一单位气体可以获得的热量。对于用作加热剂，可以根据它们的热值容易地比较来自不同来源和具有不同组成的气体的相对优点。因此，热值被用作确定托管转移天然气价格的参数。它也是计算气体等能量转换设备效率的一个重要因素- 燃烧式涡轮机。气体的热值不仅取决于温度和压力，还取决于水蒸气的饱和程度。然而，一些测量热值的量热法是基于在特定条件下被水饱和的气体。 5.2 气体的相对密度（比重）量化了在相同条件下与空气相比的气体密度。

1.1 This practice covers procedures for calculating heating value, relative density, and compressibility factor at base conditions (14.696 psia and 60 °F (15.55 °C)) for natural gas mixtures from compositional analysis. 2 1.2 This practice applies to all common types of utility gaseous fuels, for example, dry natural gas, reformed gas, oil gas (both high and low Btu), propane-air, carbureted water gas, coke oven gas, and retort coal gas, for which suitable methods of analysis as described in Section 6 are available. Calculation procedures for other base conditions are given. 1.3 Units— The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 The heating value is a measure of the suitability of a pure gas or a gas mixture for use as a fuel; it indicates the amount of energy that can be obtained as heat by burning a unit of gas. For use as heating agents, the relative merits of gases from different sources and having different compositions can be compared readily on the basis of their heating values. Therefore, the heating value is used as a parameter for determining the price of gas in custody transfer. It is also an essential factor in calculating the efficiencies of energy conversion devices such as gas-fired turbines. The heating values of a gas depend not only upon the temperature and pressure, but also upon the degree of saturation with water vapor. However, some calorimetric methods for measuring heating values are based upon the gas being saturated with water at the specified conditions. 5.2 The relative density (specific gravity) of a gas quantifies the density of the gas as compared with that of air under the same conditions.