1.1 本试验方法涵盖在150℃下实验室测定发动机机油的高温高剪切（HTHS）粘度 °C，使用包含压力、温度和计时仪器的多室毛细管粘度计。本试验方法的剪切速率对应于140万倒数秒（1.4 × 10 6. s −1. ). 3. 已发现该剪切速率可减少该试验方法与其他高剪切速率试验方法之间的差异- 高温高剪切试验方法 3. （试验方法 D4683 和 D4741 )用于发动机机油规格。粘度直接从标定中确定，标定使用标称粘度为1.4的牛顿油 150 mPa·s至5.0 mPa·s °C。仅针对粘度范围1.45确定精度 精度部分中列出的材料在150°C时为mPa·s和5.05 mPa·s。 1.2 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。 1.2.1 厘泊（cP）是一种非国际单位制粘度单位，在数值上等于毫帕秒（mPa·s）。 1.2.2 磅/平方英寸（psi）是一种非国际单位制压力单位，约等于6.895 kPa。这些单元仅供参考 6.1.1 , 7.3 , 9.1.2.1 ，以及表格。 1.3 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。 1.4 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 粘度是流体润滑剂的一个重要特性。所有液体的粘度都随温度而变化。许多常见的石油润滑剂是非牛顿的:它们的粘度也随剪切速率而变化。当在润滑剂在使用过程中所经历的剪切速率和温度条件下或接近剪切速率和温度条件下测量粘度时，润滑剂粘度的效用最大。 5.2 本试验方法的剪切速率和温度条件被认为是恶劣工况下汽车发动机轴承的代表性条件。 5.3 许多设备制造商和润滑油规格要求最低高温高剪切粘度为150 °C和10 6. s −1. . 毛细管粘度计中的剪切速率随毛细管半径而变化。增加本试验方法中墙体处的表观剪切速率，以补偿可变剪切速率。 3. 5.4 该试验在ASTM合作项目中进行了评估。 6.

1.1 This test method covers the laboratory determination of high-temperature high-shear (HTHS) viscosity of engine oils at a temperature of 150 °C using a multicell capillary viscometer containing pressure, temperature, and timing instrumentation. The shear rate for this test method corresponds to an apparent shear rate at the wall of 1.4 million reciprocal seconds (1.4 × 10 6 s −1 ). 3 This shear rate has been found to decrease the discrepancy between this test method and other high-temperature high-shear test methods 3 (Test Methods D4683 and D4741 ) used for engine oil specifications. Viscosities are determined directly from calibrations that have been established with Newtonian oils with nominal viscosities from 1.4 mPa·s to 5.0 mPa·s at 150 °C. The precision has only been determined for the viscosity range 1.45 mPa·s and 5.05 mPa·s at 150 °C for the materials listed in the precision section. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.2.1 The centiPoise (cP) is a non-SI metric unit of viscosity that is numerically equal to the milliPascal-second (mPa·s). 1.2.2 Pounds per square inch (psi) is a non-SI unit of pressure that is approximately equal to 6.895 kPa. These units are provided for information only in 6.1.1 , 7.3 , 9.1.2.1 , and the tables. 1.3 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. 1.4 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 Viscosity is an important property of fluid lubricants. The viscosity of all fluids varies with temperature. Many common petroleum lubricants are non-Newtonian: their viscosity also varies with shear rate. The usefulness of the viscosity of lubricants is greatest when the viscosity is measured at or near the conditions of shear rate and temperature that the lubricants will experience in service. 5.2 The conditions of shear rate and temperature of this test method are thought to be representative of those in the bearing of automotive engines in severe service. 5.3 Many equipment manufacturers and lubricant specifications require a minimum high-temperature high-shear viscosity at 150 °C and 10 6 s −1 . The shear rate in capillary viscometers varies across the radius of the capillary. The apparent shear rate at the wall for this test method is increased to compensate for the variable shear rate. 3 5.4 This test was evaluated in an ASTM cooperative program. 6