Air compressor increases ambient air pressure for various applications. Compressed air is stored in tanks until needed. Compressor shuts off when pressure reaches upper limit
Atmospheric pressure is the force per unit area within Earth's atmosphere. Standard atmosphere (atm) equals 101,325 Pa or 14.696 psi. Pressure decreases with increasing altitude due to less overlying mass
Air pressure is the weight of air molecules above a surface. Dry air has a molecular weight of 28.97 grams per mole. Air pressure ranges from 980 to 1050 millibars across Earth
Air pressure is the force exerted by atmospheric air on planet's surface. Pressure increases with altitude and temperature. Pressure is measured in Pascals (Pa)
Nm3 stands for "normal cubic meter". It measures gas volume under standard conditions at 0°C and 1 atm. Represents volume of one mole of gas under standard conditions
IUPAC defines STP as 0°C (273.15 K) and 105 pascals (1 bar). Imperial/USA system uses 60°F (15.6°C) and 14.696 psia (1 atm). Volume of 1 mol gas at STP is 23.6442 liters. Earlier IUAPC definition (273.15 K, 1 atm) is discontinued