Method and device for measurement of dynamic viscosity

Abstract

The paper proposes a methodology and ensuing test rig for finding the viscosity of a liquid lubricant. The principle consists in obtaining a contact between two spherical surfaces, one concave and the other one convex. One of the surfaces is kept immobile and to the other, a rotation motion is imposed around the common normal in the contact point and then the law of motion for the mobile lens is found. The law of motion allows for estimation of friction torque, dependent on viscosity at its turn. Applying the method for mineral oils, values comparable to the ones presented by the producer were obtained.