EXPLANATION
Density and viscosity are important properties of petroleum and nonpetroleum liquids. This test method provides concurrent measurements of both dynamic viscosity and density of liquid petroleum products and crude oils. The kinematic viscosity can be obtained by dividing the dynamic viscosity by density obtained at the same temperature. This test method is intended for liquids following Newtonian behavior. Although precision only in a specific range has been determined, the method should be applicable to a wider range of products.
TEST SUMMARY
The test specimen is introduced into the measuring cells, which are at a closely controlled and known temperature. The measuring cell consists of a pair of rotating concentric cylinders and an oscillating U-tube. The dynamic viscosity is determined from the equilibrium rotational speed of the inner cylinder under the influence of the shear stress of the test specimen and an eddy current brake in conjuction with adjustment data. The density is determined by oscillation frequency of the U-tube in conjuction with adjustment data.
The kinematic viscosity is calculated by dividing the dynamic viscosity by the density.
Accepted reference materials were not tested by this method, hence no statement for bias can be made.
TEST PRECISION
The method is found not to have relative bias against D445 kinematic viscosity method or D4052 density method.
