What is Atmosphere (unit)?
The '''standard atmosphere''' (symbol: '''atm''') is a unit of [[atmospheric pressure]]. It refers to the air pressure at [[sea level]] and is defined as equal to 101,325 [[Pascal (unit)|Pa]].<ref name=BIPM>[http://www.bipm.org/jsp/en/ViewCGPMResolution.jsp?CGPM=10&RES=4 BIPM Definition of the standard atmosphere]</ref> Since 1982, it has been replaced by the [[bar (unit)|bar]], which is exactly 10<sup>5</sup> Pa.<ref>IUPAC.org, Gold Book, ''[http://goldbook.iupac.org/S05921.html Standard Pressure]''</ref> The use of either unit is discouraged. == Related pages== *[[Standard temperature and pressure]] == References == {{reflist}} {{science-stub}} [[Category:Units of pressure]]