pound force per square inch
Pound force per square inch (psi) is a unit from the Imperial system defined as the pressure resulting from a force of one pound-force applied to an area of one square inch. It is used in various applications such as tire pressure and hydraulic systems.
Atmospheres
The atmosphere (atm) is a unit of pressure being equal to 101,325 pascals. It is based on the average atmospheric pressure at sea level on Earth.