1.1 ,This test method covers measurement of the ability of petroleum oils or synthetic fluids to separate from water. Although developed specifically for steam-turbine oils having viscosities of 28.8 ,mm²/s to 90 ,mm²/s at 40 ,°,C, this test method may be used to test oils of other types having various viscosities and synthetic fluids at other test temperatures. It is recommended, however, that the test temperature be raised to 82 ,°,C ±, 1 ,°,C when testing products more viscous than 90 ,mm²/s at 40 ,°,C. For higher viscosity oils where there is insufficient mixing of oil and water, Test Method D2711 is recommended. Other test temperatures such as 25 ,°,C may also be used. A 1 ,% sodium choloride (NaCl) solution or synthetic seawater may be used in place of distilled water when testing certain oils or fuels used in marine applications.