1.1 本实验室试验方法涵盖了以发动机辛烷值为单位的液体火花点火式发动机燃料的爆震额定值的定量测定，包括含有高达25的燃料 % v/v的乙醇。然而，该试验方法可能不适用于主要为含氧化合物的燃料和燃料组件。 2. 样品燃料在标准化的单缸、四冲程循环、可变压缩比、化油器、CFR发动机中根据规定的一组操作条件进行测试。 辛烷值刻度由主要参考燃料混合物的体积组成定义。将样品燃料爆震强度与一种或多种主要参考燃料混合物的爆震强度进行比较。与样品燃料的爆震强度相匹配的主要参考燃料混合物的辛烷值确定了发动机辛烷值。 1.2 辛烷值范围为0至120辛烷值，但本试验方法的工作范围为40至120辛烷数。为汽车火花生产的典型商业燃料- 点火发动机的辛烷值在80到90之间。为航空火花点火式发动机生产的典型商业燃料的辛烷值范围为98至102。对汽油混合原料或其他工艺流材料的测试可以在整个发动机辛烷值范围内产生不同水平的评级。 1.3 操作条件的值以国际单位制表示，并被视为标准。括号中的值是历史英寸磅单位。标准化CFR发动机测量值仍以英寸为单位- 磅单位，只是因为已经为该设备创建了广泛而昂贵的工具。 1.4 为了确定是否符合本标准中的所有规定限值，观测值或计算值应按照实践中的四舍五入方法，在表示规定限值时使用的最后一个右手数字中“四舍五舍五入到最接近的单位” E29 . 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。 有关更具体的危险说明，请参阅第节 8. , 14.4.1 , 15.5.1 , 16.6.1 , 附件A1 , A2.2.3.1 , A2.2.3.3 ( 6. 和 9 ), A2.3.5 , X3.3.7 , X4.2.3.1 , X4.3.4.1 , X4.3.9.3 , X4.3.12.4 和 X4.5.1.8 . 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 电机O.N.与商用汽车火花点火式发动机在恶劣工作条件下的抗爆性能相关。 5.2 发动机制造商、炼油商和营销人员使用发动机O.N.，并在商业中作为与燃料和发动机匹配相关的主要规格测量。 5.2.1 允许计算汽车抗爆性能的经验相关性基于一般方程: 的值 k 1. , k 2. 和 k 3. 随车辆和车辆数量的不同而不同，并以道路为基础- 辛烷值测定。 5.2.2 根据规范，Motor O.N.与Research O.N.一起定义了汽车火花点火式发动机燃料的抗爆指数 D4814 。燃料的抗爆指数近似于许多车辆的道路辛烷值，张贴在美国的零售分配泵上，并在车辆手册中参考。 这通常表现为: 5.3 发动机O.N.用于测量含有含氧化合物的火花点火式发动机燃料的抗爆性能。 5.4 电机O.N.对于固定式和其他非机动发动机应用中使用的火花点火式发动机燃料的规格而言是重要的。 5.5 电机O.N.用于通过相关方程确定航空方法O.N.或航空火花点火式发动机燃料的性能数（稀混合气航空额定值）。 7.

1.1 This laboratory test method covers the quantitative determination of the knock rating of liquid spark-ignition engine fuel in terms of Motor octane number, including fuels that contain up to 25 % v/v of ethanol. However, this test method may not be applicable to fuel and fuel components that are primarily oxygenates. 2 The sample fuel is tested in a standardized single cylinder, four-stroke cycle, variable compression ratio, carbureted, CFR engine run in accordance with a defined set of operating conditions. The octane number scale is defined by the volumetric composition of primary reference fuel blends. The sample fuel knock intensity is compared to that of one or more primary reference fuel blends. The octane number of the primary reference fuel blend that matches the knock intensity of the sample fuel establishes the Motor octane number. 1.2 The octane number scale covers the range from 0 to 120 octane number, but this test method has a working range from 40 to 120 octane number. Typical commercial fuels produced for automotive spark-ignition engines rate in the 80 to 90 Motor octane number range. Typical commercial fuels produced for aviation spark-ignition engines rate in the 98 to 102 Motor octane number range. Testing of gasoline blend stocks or other process stream materials can produce ratings at various levels throughout the Motor octane number range. 1.3 The values of operating conditions are stated in SI units and are considered standard. The values in parentheses are the historical inch-pounds units. The standardized CFR engine measurements continue to be in inch-pound units only because of the extensive and expensive tooling that has been created for this equipment. 1.4 For purposes of determining conformance with all specified limits in this standard, an observed value or a calculated value shall be rounded “to the nearest unit” in the last right-hand digit used in expressing the specified limit, in accordance with the rounding method of Practice E29 . 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 more specific hazard statements, see Section 8 , 14.4.1 , 15.5.1 , 16.6.1 , Annex A1 , A2.2.3.1 , A2.2.3.3 ( 6 ) and ( 9 ), A2.3.5 , X3.3.7 , X4.2.3.1 , X4.3.4.1 , X4.3.9.3 , X4.3.12.4 , and X4.5.1.8 . 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 Motor O.N. correlates with commercial automotive spark-ignition engine antiknock performance under severe conditions of operation. 5.2 Motor O.N. is used by engine manufacturers, petroleum refiners and marketers, and in commerce as a primary specification measurement related to the matching of fuels and engines. 5.2.1 Empirical correlations that permit calculation of automotive antiknock performance are based on the general equation: Values of k 1 , k 2 , and k 3 vary with vehicles and vehicle populations and are based on road-octane number determinations. 5.2.2 Motor O.N., in conjunction with Research O.N., defines the antiknock index of automotive spark-ignition engine fuels, in accordance with Specification D4814 . The antiknock index of a fuel approximates the road octane ratings for many vehicles, is posted on retail dispensing pumps in the United States, and is referred to in vehicle manuals. This is more commonly presented as: 5.3 Motor O.N. is used for measuring the antiknock performance of spark-ignition engine fuels that contain oxygenates. 5.4 Motor O.N. is important in relation to the specifications for spark-ignition engine fuels used in stationary and other nonautomotive engine applications. 5.5 Motor O.N. is utilized to determine, by correlation equation, the Aviation method O.N. or performance number (lean-mixture aviation rating) of aviation spark-ignition engine fuel. 7