1.1 本试验方法涵盖使用自动蒸气压仪器测定液化石油气产品在37.8°C温度、汽液比0.5:1、压力为200 kPa至1550 kPa、样品体积为3.33 mL时的蒸气压。 1.2 本试验方法适用于温度37.8℃~70℃、汽液比0.1:1~4:1、压力高达3500kPa的液化石油气产品蒸气压的测定；然而，测试方法的精密度（见第节 15 )仅针对0.5:1的汽液比、37.8℃的温度和300kPa至1500kPa的压力范围进行测定。 附注1: 本测试方法并非旨在测定液化石油气样品的真实蒸气压，而是测定和报告液化石油气在37℃下的蒸气压。8℃温度和0.5:1的汽液比作为试验方法 D1267 方法。 附注2: 该测试方法不是真正的蒸汽压方法，并且不会测量任何溶解气体（如氮气或氦气）的全部贡献（如果存在）。轻气体对测量蒸汽压的贡献高度依赖于测试温度、气体类型和测试的V/L比。 1.3 以SI单位表示的值将被视为标准值。 1.3.1 例外- 非SI单位包含在括号中，仅供参考。 1.4 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。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法规限制的适用性。具体警告语句，请参见 附录X2 . 1.5 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》中确立的国际公认的标准化原则制定的。 ======意义和用途====== 5.1 有关液化石油气蒸气压的信息与选择适当设计的储存容器、运输集装箱和客户使用设备有关，以确保这些产品的安全处理。 5.2 出于安全原因，确定液化石油气的蒸汽压力是重要的，以确保在正常工作温度条件下不会超过储存、处理和燃料系统的最大工作设计压力。5.3 对于液化石油气，蒸气压可以被认为是产品中存在的最易挥发物质的量的半定量测量。 5.4 该测试方法使用小的样品体积，并且排除了在高压下对测量室的任何手动操作。

1.1 This test method covers the use of automatic vapor pressure instruments to determine the vapor pressure of liquefied petroleum gas products at a temperature of 37.8 °C, vapor to liquid ratio of 0.5:1, and pressures from 200 kPa to 1550 kPa on a sample volume of 3.33 mL. 1.2 This test method is applicable to the determination of vapor pressures of liquefied petroleum gas products at temperatures from 37.8 °C to 70 °C, vapor to liquid ratios of 0.1:1 to 4:1, and pressures up to 3500 kPa; however, the precision of the test method (see Section 15 ) has only been determined for a vapor to liquid ratio of 0.5:1, at a temperature of 37.8 °C, and a pressure range from 300 kPa to 1500 kPa. Note 1: This test method is not intended to determine the true vapor pressure of LPG samples, but rather determine and report the vapor pressure of LPG at the 37.8 °C temperature and 0.5:1 vapor to liquid ratio as the Test Method D1267 method. Note 2: This test method is not a true vapor pressure method and will not measure the full contribution from any dissolved gases such as nitrogen or helium if they are present. The contribution of light gases to the measured vapor pressure is highly dependent on the test temperature, type of gas, and V/L ratio of the test. 1.3 The values stated in SI units are to be regarded as standard. 1.3.1 Exception— Non-SI units are included in parentheses for information only. 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. For specific warning statements, see Appendix X2 . 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 Information on the vapor pressures of liquefied petroleum gas is pertinent to selection of properly designed storage vessels, shipping containers, and customer utilization equipment to ensure safe handling of these products. 5.2 Determination of the vapor pressure of liquefied petroleum gas is important for safety reasons to ensure that the maximum operating design pressures of storage, handling, and fuel systems will not be exceeded under normal operating temperature conditions. 5.3 For liquefied petroleum gases, vapor pressure can be considered a semi-quantitative measure of the amount of the most volatile material present in the product. 5.4 This test method uses a small sample volume and excludes any manual handling of a measuring chamber under high pressure.