(unit of pressure)
An atm (or atmosphere) is a unit of pressure conceived to
basically match Earth's atmospheric pressure.
To make it an exact value, the chosen pressure was a selected
long-term average at sea level at the latitude of Paris, France.
- 101325 Pascal ( 1 kg·m-1·s-2 ).
- 1.01325 bar (a similar measure of pressure).
- 1013.25 millibars.
- ≈14.7 pounds-force per square inch.
water vapor planet