APPARENT VISCOSITY USING HTHS CAPILLARY VISCOMETERS
Several different configurations of capillary viscometers have been successfully used for measuring the viscosity of engine oils at the high shear rates and high temperatures that occur in engines. There are at least five methods available for this determination.
EXPLANATION
Viscosity is an important property of a fluid lubricant. Many common petroleum lubricants are non-Newtonian; their viscosity varies with shear rate. The viscosity of all fluids varies with temperature. The viscosity of lubricants is to be measured at or near the conditions of shear rate and temperature that they will experience in service. The conditions of shear rate and temperature of these test methods are thought to be representative of those in the bearings of automotive engines in severe service.
