Poise (unit): Difference between revisions

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The poise (symbol P; English: /ˈpɔɪzˌˈpwɑːz/) is the unit of dynamic viscosity (absolute viscosity) in the centimetre–gram–second system of units.^[1] It is named after Jean Léonard Marie Poiseuille.

1~{\text{P}}=0.1~{\text{kg}}\cdot {\text{m}}^{-1}\cdot {\text{s}}^{-1}=1~{\text{g}}\cdot {\text{cm}}^{-1}\cdot {\text{s}}^{-1}=1~{\text{dyne}}\cdot {\text{s}}\cdot {\text{cm}}^{-2}.

The analogous unit in the International System of Units is the pascal-second (Pa·s):^[2]

1~{\text{Pa}}\cdot {\text{s}}=1~{\text{N}}\cdot {\text{s}}\cdot {\text{m}}^{-2}=1~{\text{kg}}\cdot {\text{m}}^{-1}\cdot {\text{s}}^{-1}=10~{\text{P}}.

The poise is often used with the metric prefix centi- because the viscosity of water at 20 °C is almost exactly 1 centipoise.^[3] A centipoise is one hundredth of a poise, equal to one millipascal-second (mPa·s) in SI units (1 cP = 10⁻³ Pa·s = 1 mPa·s).^[4]

The CGS symbol for the centipoise is cP. The abbreviations cps, cp, and cPs are sometimes seen.

Liquid water has a viscosity of 0.00890 P at 25 °C and a pressure of 1 atmosphere (0.00890 P = 0.890 cP = 0.890 mPa·s).^[5]

References

^ Gooch, Jan W. (2010). Encyclopedia dictionary of polymers (2nd ed.). Berlin: Springer. ISBN 978-1-4419-6246-1.
^ Reid, Robert C. (1987). The Properties of Gases and Liquids (4th ed.). McGraw-Hill.
^ Parker, Sybil P. (1988). Fluid Mechanics Source Book (1st ed.). McGraw-Hill.
^ Lide, David R. (1994). CRC Handbook of Thermophysical and Thermochemical Data (1st ed.). CRC Press.
^ "Viscosity of Liquids", in CRC Handbook of Chemistry and Physics, 91st Edition, W.M. Haynes, ed., CRC Press/Taylor and Francis, Boca Raton, FL, 2010-2011.

[1] Gooch, Jan W. (2010). Encyclopedia dictionary of polymers (2nd ed.). Berlin: Springer. ISBN 978-1-4419-6246-1.

[2] Reid, Robert C. (1987). The Properties of Gases and Liquids (4th ed.). McGraw-Hill.

[3] Parker, Sybil P. (1988). Fluid Mechanics Source Book (1st ed.). McGraw-Hill.

[4] Lide, David R. (1994). CRC Handbook of Thermophysical and Thermochemical Data (1st ed.). CRC Press.

[5] "Viscosity of Liquids", in CRC Handbook of Chemistry and Physics, 91st Edition, W.M. Haynes, ed., CRC Press/Taylor and Francis, Boca Raton, FL, 2010-2011.

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@@ Line 8: / Line 8: @@
 :<math>1~\text{Pa} \cdot \text{s} = 1~\text{N} \cdot \text{s} \cdot \text{m}^{-2} = 1~\text{kg} \cdot \text{m}^{-1} \cdot \text{s}^{-1} = 10~\text{P}.</math>
-The poise is often used with the [[metric prefix]]<!--NB: not an SI prefix here--> ''centi-'' because the viscosity of water at 20&nbsp;°C is almost exactly 1 centipoise.<ref>{{cite book|last1=Parker|first1=Sybil P.|title=Fluid Mechanics Source Book.|date=1988|publisher=McGraw-Hill|edition=1st}}</ref> A '''centipoise''' is one hundredth of a poise, equal to one millipascal-second (mPa·s) in SI units (1 cP = 10<sup>−3</sup> Pa·s = 1 mPa·s).
+The poise is often used with the [[metric prefix]]<!--NB: not an SI prefix here--> ''centi-'' because the viscosity of water at 20&nbsp;°C is almost exactly 1 centipoise.<ref>{{cite book|last1=Parker|first1=Sybil P.|title=Fluid Mechanics Source Book.|date=1988|publisher=McGraw-Hill|edition=1st}}</ref> A centipoise is one hundredth of a poise, equal to one millipascal-second (mPa·s) in SI units (1 cP = 10<sup>−3</sup> Pa·s = 1 mPa·s).<ref>{{cite book|last1=Lide|first1=David R.|title=CRC Handbook of Thermophysical and Thermochemical Data.|date=1994|publisher=CRC Press|edition=1st}}</ref>
 The CGS symbol for the centipoise is cP.  The abbreviations cps, cp, and cPs are sometimes seen.

Revision as of 22:01, 7 August 2017

See also

References