1.1 本试验方法描述了可根据试验方法获得蒸馏数据的石油馏分燃料真实蒸气压的计算 D86 在获得90体积%的蒸馏物之前没有达到分解点。 1.2 该试验方法可用于计算燃料在0%平衡闪蒸温度和临界温度之间的温度下的蒸汽压。包括获得未知燃料的计算临界温度的规定。 1.3 石油燃料的临界压力温度数据通常不可用。但是，如果已知临界压力和临界温度，则应将这些值用作 图1 建立一个临界点，而不是如中所述建立的焦点 7.5.4 ; 以及中描述的计算 7.5 通过 7.5.4 不需要。如果已知在大气压下蒸馏0%时的确定的真实沸点或确定的平衡闪蒸温度，则应使用确定的值来确定气泡的下限- 中提到的点线 7.4 . 1.4 对于在试验方法之间沸点范围小于100°F（38°C）的馏分燃料，该方法不可靠 D86 10体积%和90体积%的蒸馏温度。 1.5 以英寸-磅单位表示的值应被视为标准值。括号中给出的值是对国际单位制的数学转换，仅供参考，不被视为标准值。 1.6 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 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 馏出燃料的真实蒸汽压是一个相对测量值，它既是燃料中最易挥发部分气化的趋势，也是防止最易挥发的部分气化所需的抑制压力。因此，当燃料用于不允许气化的应用中，并且温度压力条件预计接近燃料的真实蒸汽压时，测量非常重要。

1.1 This test method describes the calculation of true vapor pressures of petroleum distillate fuels for which distillation data may be obtained in accordance with Test Method D86 without reaching a decomposition point prior to obtaining 90 % by volume distilled. 1.2 The test method may be used to calculate vapor pressures at temperatures between the 0 % equilibrium flash temperature and the critical temperature of the fuel. Provision is included for obtaining a calculated critical temperature for fuels for which it is not known. 1.3 Critical pressure-temperature data are usually not available for petroleum fuels. However, if both the critical pressure and critical temperature are known, the values shall be used as the coordinates in Fig. 1 to establish a critical point to be used instead of the focal point established as described in 7.5.4 ; and the calculations described in 7.5 through 7.5.4 are not required. If either a determined true boiling point or determined equilibrium flash vaporization temperature at 0 % distilled at atmospheric pressure is known, the determined value shall be used to establish the lower limit of the bubble-point line referred to in 7.4 . 1.4 The method is not reliable for distillate fuels having a boiling range of less than 100 °F (38 °C) between the Test Method D86 10 % by volume and 90 % by volume distilled temperatures. 1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.6 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. 1.7 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 true vapor pressure of a distillate fuel is a relative measurement, both of the tendency of the most volatile portion of the fuel to gasify, and of the restraining pressure required to prevent gasification of the most volatile portion. Thus the measurement is of importance when a fuel is to be utilized in applications where no gasification may be tolerated, and temperature-pressure conditions are expected to be near the true vapor pressure of the fuel.