1.1 本试验方法包括使用高分辨率核磁共振（NMR）光谱仪测定未添加基础油（润滑油）烃油的总甲氢含量，该烃油在环境温度下完全可溶于氯仿。 1.2 报告的单位为甲基氢原子的摩尔百分比。对于脉冲傅立叶变换（FT）光谱仪，检测极限通常为0.1 % 摩尔氢原子。临时精度适用于范围20.5 % 至38.7 % 摩尔甲基氢。 1.3 该方法适用于含量<0的样品。 1. % 摩尔烯烃氢。 1.4 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户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。 具体预防说明见 7.2 和 7.3 . 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 甲基氢含量是碳氢化合物润滑油的一个关键特性，可以影响油的各种特性，包括其沸腾范围、粘度、低温流量和氧化稳定性。 5.2 核磁共振程序不需要已知甲基氢含量的校准标准，适用于在环境温度下完全溶于氯仿的各种碳氢化合物润滑油。

1.1 This test method covers the determination of the total methyl hydrogen content of unadditized base stock (lubricating oils) hydrocarbon oils that are completely soluble in chloroform at ambient temperature using high-resolution nuclear magnetic resonance (NMR) spectrometers. 1.2 The reported units are mol percent methyl hydrogen atoms. For pulse Fourier transform (FT) spectrometers, the detection limit is typically 0.1 % mol hydrogen atoms. The interim precision is applicable in the range 20.5 % to 38.7 % mol methyl hydrogen. 1.3 This method is applicable to samples containing <0.1 % mol olefinic hydrogens. 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. Specific precautionary statements are given in 7.2 and 7.3 . 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 Methyl hydrogen content is a key characteristic of hydrocarbon lubricating oils and can affect a variety of properties of the oil including its boiling range, viscosity, low temperature flow, and oxidation stability. 5.2 The NMR procedure does not require calibration standards of known methyl hydrogen content and is applicable to a wide range of hydrocarbon lubricating oils that are completely soluble in chloroform at ambient temperature.