The poiseuille (symbol Pl) has been proposed as a
derived SI unit of
dynamic viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
, named after the French physicist
Jean Léonard Marie Poiseuille (1797–1869).
In practice the unit has never been widely accepted and most international standards bodies do not include the poiseuille in their list of units. The third edition of the
IUPAC Green Book, for example, lists Pa⋅s (
pascal-
second) as the SI-unit for dynamic viscosity, and does not mention the poiseuille.
The equivalent CGS unit, the
poise
Poise may mean:
* Poise (unit), a measure of viscosity
* A concept similar to gracefulness
* Ferdinand Poise
image:Ferdinand Poise 1892.jpg,
Jean Alexandre Ferdinand Poise (3 June 1828 – 13 May 1892) was a French composer, mainly of opéra ...
, symbol P, is most widely used when reporting viscosity measurements.
:
Liquid water has a viscosity of at at a pressure of ( = = = ).
["Viscosity of Liquids", in CRC Handbook of Chemistry and Physics, 91st Edition, W.M. Haynes, ed., CRC Press/Taylor and Francis, Boca Raton, Florida, 2010–2011.]
References
Bibliography
* François Cardarelli (2004). ''Encyclopaedia of Scientific Units, Weights and Measures''. Springer-Verlag London Ltd.
SI units
Units of dynamic viscosity
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