what is 1 atmosphere pressure
The standard atmosphere (symbol: atm) is a unit of pressure defined as 101325 Pa (1.01325 bar).It is sometimes used as a reference or standard pressure.or example, a partial pressure of oxygen is calibrated typically using air at sea level, so is expressed in units of atm. The old European unit technical atmosphere (at) is equal to 1 kilogram-force per square centimetre (kgf/cm 2), 7004980665000000000â 98066.5 Pa.