Viscosity

Measurement of a fluid's resistance to flow. The common metric unit of absolute viscosity is the  poise, which is defined as the force in dynes required to move a surface one square centimeter in area past a parallel surface at a speed of one centimeter per second, with the surfaces separated by a fluid film one centimeter thick. In addition to kinematic viscosity, there are other methods for determining viscosity, including Saybolt Universal Viscosity (SUV), Saybolt Furol viscosity, Engier viscosity, and Redwood viscosity. Since viscosity varies in inversely with temperature, its value is meaningless until the temperature at which it is determined is reported.

Viscosity, absolute

the ration of the shearing stress to the shear rate of a fluid. It is usually expressed in centipoise.

Viscosity, kinematic

the absolute viscosity divided by the density of the fluid. It is usually expressed in centistokes.

Stoke (St)

kinematic measurement of a fluid's resistance to flow defined by the ratio of the fluid's dynamic viscosity to its density.

Poise (absolute viscosity)

a measure of viscosity numerically equal to the force required to move a plane surface of one square centimeter per second when the surfaces are separated by a layer of fluid one centimeter in thickness. It is the ratio of the shearing stress to the shear rate of a fluid and is expressed in dyne seconds per square centimeter (DYNE sec/cm²); 1 centipoise equals .01 poise.

100 Centipoise  = 1 Poise

1 Centipoise       = 1 mPa s (Millipascal Second)

1 Poise                = 0.1 Pa s (Pascal Second)

Centipoise          = Centistoke x Density

Centistoke        = Centipoise / Density

Centipoise         = 0.001 x Poise

Centistoke        = (0.01 x Poise) / Density

Poise                  = dyne x sec/ cm²

Centistoke       = (0.01 x dyne x sec/ cm²) / Density

Dyne                   = 0.00001 Newton

Centistoke      = (0.01 x 0.00001 x Newton x sec/cm²) / Density

Newton              = 10 x kg x m/sec²

Centistoke      = (0.01 x 0.00001 x 10 x kg x m/sec² x sec/ cm²) / Density

Density              = kg/cm3

Centistoke      = (0.01 x 0.00001 x 10 x kg x 100 x cm/sec² x sec/ cm²) / kg/cm³

Eliminasi satuan

Centistoke     = (0.01 x 0.00001 x 10 x kg x 100 x cm/sec² x sec/ cm²) / kg/cm³

                         = 0. 0001 cm²/sec

                         = mm²/ sec

Jadi satuan untuk centistokes adalah :

Centistoke    = mm²/sec