Abstract

This Uganda Standard covers the measurement of the yield stress and viscosity of engine oils after cooling at controlled rates over a period exceeding 45 h to a final test temperature between -10 Degrees Celsius and -40 Degrees Celsius. The precision is stated for test temperatures from -40 Degrees Celsius to -15 Degrees Celsius. 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. The viscosity as measured at this shear stress was found to produce the best correlation between the temperature at which the viscosity reached a critical value and borderline pumping failure temperature in engines. This standard was published on 2019-3-26