Standard atmosphere (symbol: atm) is a unit of pressure. Standard atmosphere is a nonSI unit that is internationally recognized. The 10th Conférence Générale des Poids et Mesures (10th CGPM) adopted standard atmosphere for general use and affirmed its definition of being precisely equal to 1,013,250 dynes per cm^{2} (101,325 Pa). This value is intended to represent the mean atmospheric pressure at mean sea level at the latitude of Paris, France, and as a practical matter, truly reflects the mean sea level pressure for many of the industrialized nations (those with latitudes similar to Paris). The former Weights and Measures office in Middlesex, England. ...
The use of water pressure  the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ...
Look up si, Si, SI in Wiktionary, the free dictionary. ...
In physics, the dyne is a unit of force specified in the centimetregramsecond (cgs) system of units, symbol dyn. One dyne is equal to exactly 105 newtons. ...
A square metre (US spelling: square meter) is by definition the area enclosed by a square with sides each 1 metre long. ...
The pascal (symbol: Pa) is the SI derived unit of pressure or stress (also: Youngs modulus and tensile strength). ...
City flag City coat of arms Motto: Fluctuat nec mergitur (Latin: Tossed by the waves, she does not sink) Paris Eiffel tower as seen from the esplanade du TrocadÃ©ro. ...
Equivalencies
A pressure of 1 atm can also be stated as:  ≡1.013 25 bar
 ≡101.325 kPa
 ≡1013.25 millibars (mbar, also mb) or hectopascals (hPa)
 ≡760 torr ^{[B]}
 ≈760.001 mmHg, 0°C, subject to revision as more precise measurements of mercury’s density become available ^{[B, C]}
 ≈29.9213 inHg, 0°C, subject to revision as more precise measurements of mercury’s density become available ^{[C]}
 ≈1.033 227 452 799 886 kgforce/cm²
 ≈1.033 227 452 799 886 technical atmosphere
 ≈1033.227 452 799 886 cm–H₂O, 4°C ^{[A]}
 ≈406.782 461 732 2385 in–H₂O, 4°C ^{[A]}
 ≈14.695 948 775 5134 poundsforce per square inch (psi)
 ≈2116.216 623 673 94 poundsforce per square foot (psf)
 ^{A} This is the customarilyaccepted value for cm–H₂O, 4°C. It is precisely the product of 1 kgforce per square centimeter (one technical atmosphere) times 1.013 25 (bar/atmosphere) divided by 0.980 665 (one gramforce). It is not accepted practice to define the value for water column based on a true physical realization of water (which would be 99.997 495% of this value because the true maximum density of Vienna Standard Mean Ocean Water is 0.999 974 95 kg/l at 3.984°C). Also, this “physical realization” would still ignore the 8.285 cm–H_{2}O reduction that would actually occur in a true physical realization due to the vapor pressure over water at 3.984°C.
 ^{B} Torr and mmHg, 0°C are often taken to be identical. For most practical purposes (to 5 significant digits), they are interchangeable.
 ^{C} NIST value of 13.595 078(5) g/ml assumed for the density of Hg at 0°C
The bar (symbol bar) and the millibar (symbol mbar, also mb) are units of pressure. ...
The pascal (symbol Pa) is the SI unit of pressure. ...
A millibar (mbar, also mb) is 1/1000th of a bar, a unit for measurement of pressure. ...
The pascal (symbol Pa) is the SI unit of pressure. ...
For the standard botanical author abbreviation Torr. ...
A technical atmosphere (symbol: at) is a nonSI unit of pressure equal to 1 kilogramforce per square centimeter, i. ...
A pressure gauge reading in PSI (red scale) and kPa (black scale) The poundforce per square inch (symbol: lbf/in2) is a nonSI unit of pressure based on avoirdupois units. ...
VSMOW, or Vienna Standard Mean Ocean Water, is an isotopic water standard defined in 1968 by the International Atomic Energy Agency. ...
As a nonregulatory agency of the United States Department of Commerce’s Technology Administration, the National Institute of Standards (NIST) develops and promotes measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life. ...
Applications In chemistry, standard temperature and pressure (STP) is defined as a reference temperature of 0°C (273.15 K) and pressure of 101.325 kPa (1 atm). In 1990, the standard pressure was changed from 1atm to an absolute pressure of 100kPa. This article or section includes a list of works cited but its sources remain unclear because it lacks intext citations. ...
In chemistry and other sciences, STP or standard temperature and pressure is a standard set of conditions for experimental measurements, to enable comparisons to be made between sets of data. ...
The degree Celsius (Â°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701â€“1744), who first proposed a similar system in 1742. ...
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The pascal (symbol Pa) is the SI unit of pressure. ...
In the United Kingdom, scuba divers and others often use the word atmosphere loosely to mean 1 bar (1000 millibars, or 100 000 Pa). Early ideas of autonomous underwater systems appear in Twenty Thousand Leagues Under the Sea Scuba Diving is the use of independent breathing equipment to stay underwater for long periods for recreational diving and professional diving. ...
The bar (symbol bar) and the millibar (symbol mbar, also mb) are units of pressure. ...
The pascal (symbol: Pa) is the SI derived unit of pressure or stress (also: Youngs modulus and tensile strength). ...
The unit technical atmosphere (at) is roughly equal to the gauge pressure under 10 m of water; 1 at = 98066.5 Pa. A technical atmosphere (symbol: at) is a nonSI unit of pressure equal to 1 kilogramforce per square centimeter, i. ...
The metre, or meter (U.S.), is a measure of length. ...
Pressure Units  Pascal (Pa)  Bar (bar)  Technical atmosphere (at)  Atmosphere (atm)  Torr (mmHg)  Poundforce per square inch (psi)  1 Pa  ≡ 1 N/m²  10^{−5}  10.197×10^{−6}  9.8692×10^{−6}  7.5006×10^{−3}  145.04×10^{−6}  1 bar  100 000  ≡ 10^{6} dyn/cm²  1.0197  0.98692  750.06  14.504  1 at  98 066.5  0.980665  ≡ 1 kgf/cm²  0.96784  735.56  14.223  1 atm  101 325  1.01325  1.0332  ≡ 1 atm  760  14.696  1 torr  133.322  1.3332×10^{−3}  1.3595×10^{−3}  1.3158×10^{−3}  ≡ 1 mmHg  19.337×10^{−3}  1 psi  6 894.76  68.948×10^{−3}  70.307×10^{−3}  68.046×10^{−3}  51.715  ≡ 1 lbf/in²  Example reading: 1 Pa = 1 N/m² = 10^{−5} bar = 10.197×10^{−6} at = 9.8692×10^{−6} atm ....etc. Note: mmHg is an abbreviation for millimetres of mercury. The pascal (symbol: Pa) is the SI derived unit of pressure or stress (also: Youngs modulus and tensile strength). ...
The bar (symbol bar) and the millibar (symbol mbar, also mb) are units of pressure. ...
A technical atmosphere (symbol: at) is a nonSI unit of pressure equal to 1 kilogramforce per square centimeter, i. ...
For the standard botanical author abbreviation Torr. ...
A pressure gauge reading in PSI (red scale) and kPa (black scale) The poundforce per square inch (symbol: lbf/in2) is a nonSI unit of pressure based on avoirdupois units. ...
The newton (symbol: N) is the SI unit of force. ...
In physics, the dyne is a unit of force specified in the centimetregramsecond (cgs) system of units, symbol dyn. One dyne is equal to exactly 105 newtons. ...
The deprecated unit kilogramforce (kgf) or kilopond (kp) is the force exerted by one kilogram of mass in standard Earth gravity (defined as exactly 9. ...
For the standard botanical author abbreviation Torr. ...
The poundforce is a nonSI unit of force or weight (properly abbreviated lbf or lbf). The poundforce is equal to a mass of one pound multiplied by the standard acceleration due to gravity on Earth (which is defined as exactly 9. ...
