IP 71 SECTION 1/96 PDF

This International Standard specifies a procedure for the determination of the kinematic viscosity, ν, of liquid petroleum products, both transparent and opaque, by measuring the time for a volume of liquid to flow under gravity through a calibrated glass capillary viscometer. The dynamic viscosity, η, can be obtained by multiplying the measured kinematic viscosity by the density, ρ, of the liquid.

NOTE 1 The result obtained from this International Standard is dependent upon the behaviour of the sample and is intended for application to liquids for which primarily the shear stress and shear rates are proportional (Newtonian flow behaviour). if, however, the viscosity varies significantly with the rate of shear. different results may be obtained from viscometers of different capillary diameters. The procedure and precision values for residual fuel oils. which under some conditions exhibit non-Newtonian behaviour. have been included.