ASTM D6896-17

1.1 This test method covers the measurement of the yield stress and viscosity of engine oils after cooling at controlled rates over a period of 43 h or 45 h to a final test temperature of -20 °C or -25 °C. The precision is stated for test temperatures -20 °C and -25 °C. The viscosity measurements are made at a shear stress of 525 Pa over a shear rate of 0.4 s^-1 to 15 s^-1. This test method is suitable for measurement of viscosities ranging from 4000 mPa·s to >400 000 mPa·s, and is suitable for yield stress measurements of 7 Pa to >350 Pa.