Viscosity

:For the image-editing utility, see: Viscosity (software)

Measurement of viscosity

Viscosity is measured with various types of viscometer, typically at 25°C (standard state).

Related Topics:
Viscometer - Standard state

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Units

Viscosity (dynamic viscosity)

The SI physical unit of dynamic viscosity is the pascal-second (Pa·s), which is identical to 1 N·s/m2 or 1 kg/(m·s). In France there have been some attempts to establish the poiseuille (Pl) as a name for the Pa·s but without international success. Care must be taken in not confusing the poiseuille with the poise named after the same person!

Related Topics:
SI - Physical unit - Pascal - Second - N - M - Kg - France - Poise

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The cgs physical unit for dynamic viscosity is the poise (P) named after Jean Louis Marie Poiseuille. It is more commonly expressed, particularly in ASTM standards, as centipoise (cP). The centipoise is commonly used because water has a viscosity of 1.0020 cP (at 20 °C; the closeness to one is a convenient coincidence).

Related Topics:
Cgs - Physical unit - Jean Louis Marie Poiseuille - ASTM

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1 poise = 100 centipoise = 1 g/(cm·s) = 0.1 Pa·s.

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1 centipoise = 1 mPa·s.

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Kinematic viscosity

The SI physical unit of kinematic viscosity is the (m2/s). The cgs physical unit for kinematic viscosity is the stokes (abbreviated S or St), named after George Gabriel Stokes . It is sometimes expressed in terms of centistokes (cS or cSt). In U.S. usage, stoke is sometimes used as the singular form.

Related Topics:
Stokes - George Gabriel Stokes

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1 stokes = 100 centistokes = 1 cm2/s = 0.0001 m2/s.

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