1.1 这些试验方法包括通过还原热解定量测定汽油和甲醇燃料中的总氧。 1.2 精度数据为1.0 % 至5.0 % 氧气（按质量计）  汽油和40 % 至50 % 氧气（按质量计）  在甲醇燃料中。 1.3 几种类型的仪器可以满足这些测试方法的要求。仪器可以在检测和定量含氧物质的方式上有所不同。然而，这些测试方法的相似之处在于燃料在富含碳的环境中热解。 1.4 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 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。 1.6 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 这些试验方法涵盖了汽油和甲醇燃料中总氧的测定，是对试验方法的补充 D4815 ，涵盖了汽油中几种特定含氧化合物的测定。 5.2 汽油中含氧化合物的存在可以促进更完全的燃烧，从而减少一氧化碳的排放。《清洁空气法》（1992年）要求在某些特定地理区域内销售的汽油含有最低质量百分比的氧气（目前为2。 7. % 以质量计）。可以通过混合甲基等化合物来满足这一要求 第三级 丁基醚、乙基 第三级 丁基醚和乙醇加入汽油中。这些试验方法包括总氧的定量测定，总氧是规定的参数。 5.2.1 美国只有七个州有这样的冬季要求，其他获得美国环保局批准的州则选择退出该计划。现在的最低氧气限值从1.8变化 % 至3.5质量%。对于甲醇/重醇混合物EPA豁免，允许的最大含氧量为3.5 % 或3.7质量%。 5.2.1.1 在美国，只有乙醇用于这种混合。由于水污染问题，一些州禁止使用乙醚，并非所有州都使用乙醚。

1.1 These test methods cover the quantitative determination of total oxygen in gasoline and methanol fuels by reductive pyrolysis. 1.2 Precision data are provided for 1.0 % to 5.0 % oxygen by mass  in gasoline and for 40 % to 50 % oxygen by mass  in methanol fuels. 1.3 Several types of instruments can be satisfactory for these test methods. Instruments can differ in the way that the oxygen-containing species is detected and quantitated. However, these test methods are similar in that the fuel is pyrolyzed in a carbon-rich environment. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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. 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 These test methods cover the determination of total oxygen in gasoline and methanol fuels, and they complement Test Method D4815 , which covers the determination of several specific oxygen-containing compounds in gasoline. 5.2 The presence of oxygen-containing compounds in gasoline can promote more complete combustion, which reduces carbon monoxide emissions. The Clean Air Act (1992) requires that gasoline sold within certain specified geographical areas contain a minimum percent of oxygen by mass (presently 2.7 % by mass) during certain portions of the year. The requirement can be met by blending compounds such as methyl tertiary butyl ether, ethyl tertiary butyl ether, and ethanol into the gasoline. These test methods cover the quantitative determination of total oxygen which is the regulated parameter. 5.2.1 Only seven U.S. states have such wintertime requirements, and others with EPA approval have opted out of the program. The minimum oxygen limit now varies from 1.8 % to 3.5 % by mass. For methanol/heavier alcohol blend EPA waivers, the maximum oxygen content allowed is 3.5 % or 3.7 % by mass. 5.2.1.1 Only ethanol is used for such blending in the U.S. Ethers are banned by some states and are not used in all states because of water contamination issues.