Method description:
A modified Couette measurement principle is used. The method has a cell for measuring density and a cell for measuring dynamic viscosity. The kinematic viscosity is calculated automatically, based on the dynamic viscosity and density of the sample.
Interpretation of results:
Viscosity is usually determined at 40 and 100 °C, from which the viscosity index – a parameter describing the temperature dependence of viscosity – can be determined. The WL is characteristic of different oil types. The oil base and the type of additives used are important.
A viscosity test informs the user whether the oil used is as required. An increase in viscosity can inform of contamination/mixing, ageing, evaporation of the oil, a decrease in viscosity on the other hand of dilution/mixing, cracking or mechanical degradation (shear stress).
