ASTM D2161-04 PDF

1.1 This practice covers the conversion tables and equations for converting kinematic viscosity in centistokes (cSt) at any temperature to Saybolt Universal viscosity in Saybolt Universal seconds (SUS) at the same temperature and for converting kinematic viscosity in centistokes at 122 and 210°F to Saybolt Furol viscosity in Saybolt Furol seconds (SFS) at the same temperatures. Kinematic viscosity values are based on water being 1.0038 mm2/s (cSt) at 68°F (20°C).

Note 1-A fundamental and preferred method for measuring kinematic viscosity is by use of kinematic viscometers as outlined in Test Method D445, It is recommended that kinematic viscosity be reported in centistokes, instead of Saybolt Universal Seconds (SUS) or Saybolt Furol Seconds (SFS). Thus this method is being retained for the purpose of calculation of kinematic viscosities from SUS and SFS data which appear in past literature. One centistokes equals one millimetre squared per second (mm2/s).

1.2 The SI unit of kinematic viscosity, mm2/s, and temperature in degrees Fahrenheit are the standard in this practice.