1.1 本试验方法涵盖了使用自动蒸汽压仪器测定石油产品和液体燃料总蒸汽压的程序。本试验方法适用于测试沸点高于0的样品 °C（32 °F），其蒸汽压在7 kPa和110 kPa（1.0 psi和16 psi）37.8 °C（100 °F），汽液比为4:1。本试验方法适用于含氧化物的汽油。未考虑样品中的溶解水。 注1: 由于外部大气压力不影响合成蒸汽压，因此该蒸汽压为37.8时的绝对压力 °C（100 °F），单位为kPa（psi）。由于样品和溶解空气少量蒸发到密闭空间的空气中，该蒸汽压不同于样品的真实蒸汽压。 1.1.1 当冷却到0时，一些汽油含氧混合物可能会出现雾状 °C至1 °C 8.5 ，应在结果报告中注明。模糊样本的精度和偏差声明尚未确定（见 附注6 ). 1.2 本试验方法是对试验方法的修改 D5191 （微型方法），其中在样品注入之前，试验箱处于大气压力下。 1.3 本试验方法涵盖使用自动蒸汽压仪器，该仪器对液体样本大小进行测量，测量范围为1 mL至10 毫升。 1.4 本试验方法适用于通过相关方程测定汽油和汽油含氧混合物的干蒸汽压当量（DVPE）（见 13.2 ). 当采用试验方法进行试验时，计算的DVPE被认为与在相同材料上获得的结果等效 D4953 . 1.5 以国际单位制表示的数值应视为标准。括号中给出的值仅供参考。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户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。 （有关具体的警告声明，请参阅 7.2 通过 7.7 .) 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）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》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 蒸汽压是挥发性液体的重要物理性质。 5.2 蒸汽压对汽车和航空汽油都至关重要，影响启动、预热以及在高工作温度或高海拔下蒸汽锁定的趋势。在某些地区，作为控制空气污染的一项措施，汽油的最大蒸汽压限制是法定的。

1.1 This test method covers a procedure for the determination of total vapor pressure of petroleum products and liquid fuels using automatic vapor pressure instruments. The test method is suitable for testing samples with boiling points above 0 °C (32 °F) that exert a vapor pressure between 7 kPa and 110 kPa (1.0 psi and 16 psi) at 37.8 °C (100 °F) at a vapor-to-liquid ratio of 4:1. The test method is applicable to gasolines containing oxygenates. No account is made of dissolved water in the sample. Note 1: Because the external atmospheric pressure does not influence the resultant vapor pressure, this vapor pressure is an absolute pressure at 37.8 °C (100 °F) in kPa (psi). This vapor pressure differs from the true vapor pressure of the sample due to some small vaporization of the sample and dissolved air into the air of the confined space. 1.1.1 Some gasoline-oxygenate blends may show a haze when cooled to 0 °C to 1 °C. If a haze is observed in 8.5 , it shall be indicated in the reporting of results. The precision and bias statements for hazy samples have not been determined (see Note 6 ). 1.2 This test method is a modification of Test Method D5191 (Mini Method) in which the test chamber is at atmospheric pressure prior to sample injection. 1.3 This test method covers the use of automated vapor pressure instruments that perform measurements on liquid sample sizes in the range from 1 mL to 10 mL. 1.4 This test method is suitable for the determination of the dry vapor pressure equivalent (DVPE) of gasoline and gasoline-oxygenate blends by means of a correlation equation (see 13.2 ). The calculated DVPE is considered equivalent to the result obtained on the same material when tested by Test Method D4953 . 1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 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. (For specific warning statements, see 7.2 through 7.7 .) 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 Vapor pressure is an important physical property of volatile liquids. 5.2 Vapor pressure is critically important for both automotive and aviation gasolines, affecting starting, warm-up, and tendency to vapor lock with high operating temperatures or high altitudes. Maximum vapor pressure limits for gasoline are legally mandated in some areas as a measure of air pollution control.