SONIC SHEAR STABILITY OF POLYMER-CONTAINING OILS: ASTM D2603
EXPLANATION
This test method covers the evaluation of the shear stability of an oil sample containing polymer in terms of the permanent loss in viscosity that results from irradiating an oil sample in a sonic oscillator. This test method can be useful in predicting the continuity of this property in an oil where no change is made in the base stock or the polymer. It is not intended to predict the performance of the polymer-containing oils in service. This test method has been successfully applied to hydraulic fluids, transmission fluids, tractor fluids, and other fluids of similar applications. It is applicable to both readily sheared and shear-resistant polymers. Correlation with performance in the case of automotive engine applications has not been established.
Some of the parts for this test may not be available; Test Methods ASTM D6278 and ASTM D5275 are alternative tests for this work.
TEST SUMMARY
Polymer-containing oil is irradiated in a sonic oscillator for a period of time and the change in viscosity of the oil is determined by Test Method ASTM D445. Standard reference fluids containing either a readily sheared or shear-resistant polymer are run frequently to ensure that the equipment imparts a controlled amount of sonic energy to the sample.
TEST PRECISION
Repeatability: 1.6 %
Reproducibility: 3.3 %
This test method has no bias.
