|1 atm in ...||... is equal to ...|
|SI units||101.325 kPa|
|U.S. customary units||14.69595 psi|
It was originally defined as the pressure exerted by 760 mm of mercury at 0 °C and standard gravity (g = 9.80665 m/s2). It was used as a reference condition for physical and chemical properties, and was implicit in the definition of the Centigrade (later Celsius) scale of temperature by defining 100 °C as being the boiling point of water at this pressure. In 1954, the 10th Conférence Générale des Poids et Mesures (CGPM) adopted standard atmosphere for general use and affirmed its definition of being precisely equal to 1013250 dynes per square centimetre (101325 Pa). This defined both temperature and pressure independent of the properties of particular substance. In addition (the CGPM noted) there had been some misapprehension that it "led some physicists to believe that this definition of the standard atmosphere was valid only for accurate work in thermometry."
In chemistry and in various industries, the reference pressure referred to in “Standard Temperature and Pressure” (STP) was commonly 1 atm (101.325 kPa) but standards have since diverged; in 1982, the International Union of Pure and Applied Chemistry (IUPAC) recommended that for the purposes of specifying the physical properties of substances, “standard pressure” should be precisely 100 kPa (1 bar).
|Pascal||Bar||Technical atmosphere||Standard atmosphere||Torr||Pounds per square inch|
|1 Pa||≡ 1 N/m2||10−5||1.0197×10−5||9.8692×10−6||7.5006×10−3||0.000 145 037 737 730|
|1 bar||105||≡ 100 kPa
≡ 106 dyn/cm2
|1.0197||0.98692||750.06||14.503 773 773 022|
|1 at||98066.5||0.980665||≡ 1 kgf/cm2||0.967 841 105 354 1||735.559 240 1||14.223 343 307 120 3|
|1 atm||101325||1.01325||1.0332||1||760||14.695 948 775 514 2|
|1 Torr||133.322 368 421||0.001 333 224||0.001 359 51||1/ ≈ 0.001 315 789||1 Torr
≈ 1 mmHg
|0.019 336 775|
|1 lbf/in2||6894.757 293 168||0.068 947 573||0.070 306 958||0.068 045 964||51.714 932 572||≡ 1 lbf/in2|
A pressure of 1 atm can also be stated as:
Scuba divers and others use the word atmosphere and "atm" in relation to pressures that are relative to mean atmospheric pressure at sea level (1.013 bar). For example, a partial pressure of oxygen is calibrated typically using air at sea level, so is expressed in units of atm.
ATM or atm may refer to:
Atmosphere (unit) or atm, a unit of atmospheric pressure
Automated teller machine, a cash dispenser or cash machineAtmos
Atmos may refer to:
An abbreviation for the Earth's atmosphere
The atmosphere (unit), a unit of pressureIt may also refer to:
ATMOS (festival) The Technical Festival of BITS Pilani Hyderabad Campus
Atmos Energy Corporation, a U.S. energy company
Atmos clock, a clock manufactured by Jaeger-LeCoultre, which runs on changes in ambient temperature
Oric Atmos, a home computer first marketed in 1984
Ambience (sound recording)
Dolby Atmos surround sound format
ATMOS Software, an Australian computer and video game company
Atmos (comics), a minor character in the 30th century DC Universe
Atmos Heating Systems, a British supplier of industrial and domestic heaters, including the Drainfree Condensing Boiler, and solar heating systems
ATMOS (ATMospheric Omission System), fictional technology that appears in the 2008 Doctor Who two-part serial "The Sontaran Stratagem" / "The Poison Sky"
ATMOS 2000, a self-propelled Israeli artillery system produced by Soltam Systems Ltd
EMC Atmos, a clustered computer storage system from EMC Corporation
Workshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems (ATMOS)
Atmos, a summonable minion in the Playstation game Final Fantasy IX.Atmosphere (disambiguation)
An atmosphere is a gas layer around a celestial body.
Atmosphere may also refer to:
Atmosphere (unit), a unit of pressure
Atmosphere of Earth
Stellar atmosphereBottled gas
Bottled gas is a term used for substances which are gaseous at standard temperature and pressure (STP) and have been compressed and stored in carbon steel, stainless steel, aluminum, or composite bottles known as gas cylinders.CSIRO Oceans and Atmosphere
CSIRO Oceans and Atmosphere (O&A) is one of the current 8 Business Units (formerly: Flagships) of the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia's largest government-supported science research agency.Cabin pressurization
Cabin pressurization is a process in which conditioned air is pumped into the cabin of an aircraft or spacecraft, in order to create a safe and comfortable environment for passengers and crew flying at high altitudes. For aircraft, this air is usually bled off from the gas turbine engines at the compressor stage, and for spacecraft, it is carried in high-pressure, often cryogenic tanks. The air is cooled, humidified, and mixed with recirculated air if necessary, before it is distributed to the cabin by one or more environmental control systems. The cabin pressure is regulated by the outflow valve.Standard atmosphere
Standard atmosphere may refer to:
A standard reference value for air pressure:
Atmosphere (unit), an approximation of the value at sea level
Atmospheric pressure, other reference values
One of various static atmospheric models of how atmospheric pressure, density, and temperature vary with altitude, such as:
The U.S. Standard Atmosphere, a series of models that give values for pressure, density, and temperature over a range of altitudes
The International Standard Atmosphere (ISA), an international standard model, defining typical atmospheric properties with altitude, at mid-latitudeThermochemical cycle
Thermochemical cycles combine solely heat sources (thermo) with chemical reactions to split water into its hydrogen and oxygen components. The term cycle is used because aside of water, hydrogen and oxygen, the chemical compounds used in these processes are continuously recycled.
If work is partially used as an input, the resulting thermochemical cycle is defined as a hybrid one.Torr
The torr (symbol: Torr) is a unit of pressure based on an absolute scale, now defined as exactly 1/760 of a standard atmosphere (101325 Pa). Thus one torr is exactly 101325/760 pascals (≈ 133.32 Pa).
Historically, one torr was intended to be the same as one "millimeter of mercury". However, subsequent redefinitions of the two units made them slightly different (by less than 0.000015%). The torr is not part of the International System of Units (SI), but it is often combined with the metric prefix milli to name one millitorr (mTorr) or 0.001 Torr.
The unit was named after Evangelista Torricelli, an Italian physicist and mathematician who discovered the principle of the barometer in 1644.