This International Standard specifies a method for measuring the ability of petroleum oils or synthetic fluids to separate from water. Recommended test temperatures are 54 + 2 °C and 82 ± 1 °C, the latter being used when the viscosity at 40 °C is more than 90 cSt*.
NOTE — Although developed specifically for steam-turbine oils having viscosities of 32 to 95 cSt at 40 °C, this method may be used to test oils of other types having various viscosities, and synthetic fluids. It is recommended that the test temperature be raised to 82 ± 1 °C when testing products more viscous than 90 cSt at 40 °C. Other test temperatures may also be used.
This method may be unsuitable for high viscosity oils where it is ap-parent that there is insufficient mixing of oil and water during stirring.
When testing synthetic fluids whose densities are greater than that of water, the procedure is unchanged, but it should be noted that the water will probably float on the emulsion or liquid.