Pascal (unit)

pascal
A pressure gauge reading in psi (red scale) and kPa (black scale)
General information
Unit systemSI
Unit ofpressure or stress
SymbolPa
Named afterBlaise Pascal
Conversions
1 Pa in ...... is equal to ...
   SI base units:   kgm−1s−2
   US customary units:   1.45038×10−4 psi
   atmosphere:   9.86923×10−6 atm
   bar:   10−5 bar
   barye (CGS unit)   10 Ba

The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI). It is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is an SI coherent derived unit defined as one newton per square metre (N/m2).[1] It is also equivalent to 10 barye (10 Ba) in the CGS system. Common multiple units of the pascal are the hectopascal (1 hPa = 100 Pa), which is equal to one millibar, and the kilopascal (1 kPa = 1000 Pa), which is equal to one centibar.

The unit of measurement called standard atmosphere (atm) is defined as 101325 Pa.[2] Meteorological observations typically report atmospheric pressure in hectopascals per the recommendation of the World Meteorological Organization, thus a standard atmosphere (atm) or typical sea-level air pressure is about 1013 hPa. Reports in the United States typically use inches of mercury[3] or millibars (hectopascals).[4][5] In Canada, these reports are given in kilopascals.[6]

  1. ^ International Bureau of Weights and Measures (2006), The International System of Units (SI) (PDF) (8th ed.), p. 118, ISBN 92-822-2213-6, archived (PDF) from the original on 4 June 2021, retrieved 16 December 2021
  2. ^ "Definition of the standard atmosphere". BIPM. Retrieved 16 February 2015.
  3. ^ "National Weather Service glossary page on inches of mercury".
  4. ^ "US government atmospheric pressure map".
  5. ^ "The Weather Channel".
  6. ^ Canada, Environment (16 April 2013). "Canadian Weather - Environment Canada". weather.gc.ca.