1.1 本试验方法包括烃类液体及其蒸馏残留物酸度的定性测定。( 警告- 许多碳氢化合物液体极其易燃。吸入有害。碳氢化合物液体蒸汽可引起闪火。） 1.2 如果需要测定烃类液体的碱度，请按照 9.2 或 9.3 ，但用3滴酚酞指示剂溶液代替甲基橙指示剂。当使用酚酞时，水溶液中的粉红色或红色表示碱性。 1.3 通过该测试方法获得的结果是定性表达式。然而，对于试剂的制备和程序，可接受的国际单位制单位应被视为标准。 1.4 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 作为精炼过程的一部分，一些石油产品用矿物酸处理。 显然，石油产品中任何残留的矿物酸都是不可取的。在烃液体的蒸馏残留物或水提取物的酸度测试中没有阳性指示，这保证了在精炼燃料或溶剂时要小心。

1.1 This test method covers the qualitative determination of the acidity of hydrocarbon liquids and their distillation residues. ( Warning— Many hydrocarbon liquids are extremely flammable. Harmful if inhaled. Hydrocarbon liquid vapors can cause a flash fire.) 1.2 If desired to determine the basicity of a hydrocarbon liquid, proceed in accordance with 9.2 or 9.3 , but substitute 3 drops of phenolphthalein indicator solution for the methyl orange indicator. A pink or red color in the aqueous solution when phenolphthalein is used indicates basicity. 1.3 The results obtained by this test method are qualitative expressions. However, for the preparation of reagents and in the procedure, acceptable SI units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety problems, 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 Some petroleum products are treated with mineral acid as part of the refining procedure. Obviously, any residual mineral acid in a petroleum product is undesirable. The absence of a positive indication in the test for acidity of the distillation residue or aqueous extract of a hydrocarbon liquid is an assurance of the care used in refining the fuel or solvent.