Viscosity is usually measured by a viscometer. The time in seconds is noted for a specified quantity of fluid to flow through a short tube of small bore under prescribed head and temperature condition. The viscosity is reported in seconds.
The Saybolt Universal viscometer is used for fluids of light to medium viscosity. The Saybolt Fural has a tube of larger bore and is used for heavier fluids.
Viscosities in centipoises can be found from Saybolt Universal seconds t by the following equations