ASTM D2603 – Sonic Shear Stability of Polymer-Containing Oils
Hydraulic fluids, transmission fluids, tractor fluids and other power transmission fluids experience shearing during normal operations, which may change the viscosity and decrease efficiency. Polymers are added to improve the viscosity index of these fluids. This test determines viscosity changes in polymer-containing fluids exposed to sonic shearing vibrations.
The viscosity of the sample is determined. The sample is then placed in the test beaker, brought to the test temperature and irradiated using a sonic horn for the time specified in the test. The resulting viscosity of the fluid is determined. The percent change in viscosity is reported.