Atmosphere (unit)

The standard atmosphere (symbol: atm) is a unit of atmospheric pressure that refers to the air pressure at sea level. It is defined as equal to 101325 Pa.^[1] Since 1982, it has been replaced by the bar, which is equal to exactly 10⁵ Pa.^[2] The usage of either unit is discouraged.

References

↑ BIPM Definition of the standard atmosphere
↑ IUPAC.org, Gold Book, Standard Pressure

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[BIPM-1] BIPM Definition of the standard atmosphere

[2] IUPAC.org, Gold Book, Standard Pressure

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