ASTM D2603 Test Method for Sonic Shear Stability of Polymer-Containing Oils
8. Procedure
8.1 Clean the sonic horn with a suitable solvent and calibrate the apparatus as described in 7.3 and 7.4. Introduce 30 mL of the sample into a clean 50-mL Griffin beaker and immerse in the constant temperature bath at the desired temperature (0°C unless otherwise specified). The beaker must be in a vertical position. Allow the sample to equilibrate for 10 min. Immerse the sonic horn in the fluid as described in 7.3. Irradiate the sample at exactly the same energy level and for the same time as determined in 7.3 and 7.4. Upon completion of irradiation, remove the sample and clean the sonic horn with a suitable solvent.
8.2 Determine the viscosity of the sample by Test Method D445 before and after irradiation.
9. Calculation
9.1 Calculate the percentage loss of viscosity as follows:
Viscosity loss, % = [(V0 - Vf)/V0] x 100
where:
V0 = viscosity of oil before irradiation, mm2/s (cSt), and
Vf = viscosity of oil after irradiation, mm 2/s (cSt).
The permanent shear stability index (PSSI) may also be calculated in accordance with Practice D6022, provided the base fluid viscosity is known.
