Development of ASTM Standard Test Methods for Measuring Engine Oil Viscosity Using Rotational Viscometers at High-Temperature and High-Shear Rates
SourceTwo ASTM standards have been developed for the measurement of engine oil viscosity at high temperature (150°C) and high shear rate (106 s-1) using rotational viscometers. Both methods resulted from significant international participation at the working group level. One test method resulted from work done primarily within ASTM Committee D-2, Subcommittee 7, using the tapered bearing simulator. The other resulted from work done within the Co-ordinating European Council (CEC) using the Ravenfield viscometer, herein called the tapered plug viscometer. The chronological development of each standard is reviewed, and test method and precision are compared. Expansion of measurement capabilities are discussed with regard to the study of lubricant rheology and engine performance.