1.1 本试验方法涵盖了石油粘度重力常数（VGC）的计算 2. 粘度超过5.5mm 2. /s在40°C（104°F）时超过0.8 mm 2. /s在100°C（212°F）时。 1.2 附件A1 描述了一种根据Saybolt（SUS）粘度和相对密度计算VGC的方法。 1.3 以国际单位制表示的值应被视为标准值。本标准不包括其他计量单位。 1.3.1 运动粘度的国际单位为毫米 2. s 1.3.2 例外情况-- 本实践中使用华氏温度单位，因为它们被行业接受用于本实践中描述的传统转换类型。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。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 粘度重力常数（VGC）是一个用于近似表征石油粘性馏分的有用函数。 2. 它对分子量相对不敏感，并且与以某些结构元素表示的流体组成有关。VGC值接近0.800表示样品具有石蜡特征，而接近1.00表示芳香结构占主导地位。与其他碳氢化合物成分指标一样，VGC不应不加选择地应用于残油、沥青材料或含有大量非碳氢化合物的样品。

1.1 This test method covers the calculation of the viscosity-gravity constant (VGC) of petroleum oils 2 having viscosities in excess of 5.5 mm 2 /s at 40 °C (104 °F) and in excess of 0.8 mm 2 /s at 100 °C (212 °F). 1.2 Annex A1 describes a method for calculating the VGC from Saybolt (SUS) viscosity and relative density. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3.1 The SI unit of kinematic viscosity is mm 2 /s. 1.3.2 Exception— Fahrenheit temperature units are used in this practice because they are accepted by industry for the type of legacy conversions described in this practice. 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. 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 The viscosity-gravity constant (VGC) is a useful function for the approximate characterization of the viscous fractions of petroleum. 2 It is relatively insensitive to molecular weight and is related to a fluids composition as expressed in terms of certain structural elements. Values of VGC near 0.800 indicate samples of paraffinic character, while values close to 1.00 indicate a preponderance of aromatic structures. Like other indicators of hydrocarbon composition, the VGC should not be indiscriminately applied to residual oils, asphaltic materials, or samples containing appreciable quantities of nonhydrocarbons.