1.1 本试验方法包括使用自动蒸气压仪器，以确定含空气、挥发性液体石油产品和液体燃料在真空中施加的总蒸气压，包括含或不含含含氧化合物的汽车火花点火燃料，以及乙醇混合物高达85 % （体积分数）（见 注1 ). 本试验方法适用于测试沸点高于0的样品 摄氏度（32 °F）之间的蒸汽压 千帕和130 千帕（1.0 psi和18.6 psi）在37.8 摄氏度（100 °F），汽液比为4:1。在1 毫升至10 毫升。 不考虑样品中的溶解水。 注1: 精度（见第节 16 )使用1 L容器在2003年实验室间研究（ILS）中确定； 2. 精度使用250 mL容器在2016年ILS中确定。 3. 注2: 样品也可以在其他汽液比、温度和压力下进行测试，但精度和偏差声明不适用。 注3: ILS于1988年、1991年、2003年和2016年进行，以确定试验方法中的精度声明 D5191 样本组中不包括任何原油。测试方法 D6377 以及IP 481已被证明适用于原油的蒸汽压力测量。 1.1.1 一些汽油含氧化合物混合物在冷却至0时可能会显示雾度 摄氏度至1度 摄氏度。如果在中观察到烟雾 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15 ). 1.2 本试验方法适用于通过相关方程计算汽油和含氧汽油混合物的干蒸汽压当量（DVPE）（见 等式1 在里面 14.2 ). 计算的DVPE非常接近通过试验方法进行试验时在相同材料上获得的干蒸汽压 D4953 . 1.3 以国际单位制表示的数值应视为标准值。 SI单位后括号中给出的值仅供参考，不被视为标准值。 1.4 警告 -许多监管机构已将汞指定为可能导致严重医疗问题的危险物质。汞或其蒸气已被证明对健康有害，对材料具有腐蚀性。处理含汞和含汞产品时要小心。有关更多信息，请参阅适用的产品安全数据表（SDS）。当地或国家法律禁止销售含汞或含汞产品，或两者兼而有之。用户必须确定其所在地销售的合法性。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的用户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。 有关具体的安全警告声明，请参见 7.2 通过 7.8 . 1.6 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一个非常重要的物理性质。 5.2 汽油和汽油含氧混合物的蒸汽压由各种政府机构调节。 5.3 挥发性石油产品的规范通常包括蒸汽压力限制，以确保产品具有适当的挥发性性能。 5.4 该试验方法比试验方法更精确 D4953 ，使用小样本量（1 毫升至10 并且需要约7 min完成测试。

1.1 This test method covers the use of automated vapor pressure instruments to determine the total vapor pressure exerted in vacuum by air-containing, volatile, liquid petroleum products and liquid fuels, including automotive spark-ignition fuels with or without oxygenates and with ethanol blends up to 85 % (volume fraction) (see Note 1 ). This test method is suitable for testing samples with boiling points above 0 °C (32 °F) that exert a vapor pressure between 7 kPa and 130 kPa (1.0 psi and 18.6 psi) at 37.8 °C (100 °F) at a vapor-to-liquid ratio of 4:1. Measurements are made on liquid sample sizes in the range from 1 mL to 10 mL. No account is made for dissolved water in the sample. Note 1: The precision (see Section 16 ) using 1 L containers was determined in a 2003 interlaboratory study (ILS); 2 the precision using 250 mL containers was determined in a 2016 ILS. 3 Note 2: Samples can also be tested at other vapor-to-liquid ratios, temperatures, and pressures, but the precision and bias statements need not apply. Note 3: The ILS conducted in 1988, 1991, 2003, and 2016 to determine the precision statements in Test Method D5191 did not include any crude oil in the sample sets. Test Method D6377 , as well as IP 481, have been shown to be suitable for vapor pressure measurements of crude oils. 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 15 ). 1.2 This test method is suitable for calculation of the dry vapor pressure equivalent (DVPE) of gasoline and gasoline-oxygenate blends by means of a correlation equation (see Eq 1 in 14.2 ). The calculated DVPE very closely approximates the dry vapor pressure that would be obtained on the same material when tested by Test Method D4953 . 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.4 WARNING —Mercury has been designated by many regulatory agencies as a hazardous substance that can cause serious medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Use Caution when handling mercury and mercury-containing products. See the applicable product Safety Data Sheet (SDS) for additional information. The potential exists that selling mercury or mercury-containing products, or both, is prohibited by local or national law. Users must determine legality of sales in their location. 1.5 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 safety warning statements, see 7.2 through 7.8 . 1.6 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 a very important physical property of volatile liquids. 5.2 The vapor pressure of gasoline and gasoline-oxygenate blends is regulated by various government agencies. 5.3 Specifications for volatile petroleum products generally include vapor pressure limits to ensure products of suitable volatility performance. 5.4 This test method is more precise than Test Method D4953 , uses a small sample size (1 mL to 10 mL), and requires about 7 min to complete the test.