Standard temperature and pressure

In chemistry, the term standard temperature and pressure (abbreviated STP) denotes an exact reference temperature of 0°C (273.15 K) and pressure of 1 atm (defined as 101.325 kPa).\nThese values approximate freezing temperature of water and atmospheric pressure at sea level. The chemical term standard ambient temperature and pressure (SATP) denotes 25°C and 100 kPa. The Army Standard Metro atmosphere, now used only in ballistics, defines sea-level conditions as 29.5275 inHg of pressure (99.9916 kPa), 59°F (15°C), and 78% humidity. (Ref: U.S. Army Ballistic Research Laboratory, U.S. Army Aberdeen Proving Ground) The International Civil Aviation Organisation (ICAO) defines the sea-level International Standard Atmosphere (ISA) as 101.325 kPa, 15°C and 0% humidity. These values provide a reference for calculating various aircraft performance figures, such as endurance, range, airspeed, and fuel consumption. When used to calculate performance at any pressure altitude other than sea level, the temperature is adjusted using the prescribed dry adiabatic lapse rates (which are -6,5°C/km for the first 11 km).\n(Ref: Manual of the ICAO Standard Atmosphere (extended to 80 kilometres (262 500 feet)), Doc 7488 / Third Edition, 1993) See also:\n* standard state\n* Standard Ambient Temperature and Pressure\n* Army Standard Metro\n* International Standard Atmosphere \n\n\n\nsimple:Standard temperature and pressure\n