![]() ![]() ![]() Pressure units and equivalencies Pressure unitsĪ pressure of 1 atm can also be stated as: In chemistry and in various industries, the reference pressure referred to in standard temperature and pressure was commonly 1 atm (101.325 kPa) but standards have since diverged in 1982, the International Union of Pure and Applied Chemistry recommended that for the purposes of specifying the physical properties of substances, standard pressure should be precisely 100 kPa (1 bar). In addition, the CGPM noted that 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." This defined both temperature and pressure independent of the properties of particular substance. ![]() In 1954, the 10th General Conference on Weights and Measures (CGPM) adopted standard atmosphere for general use and affirmed its definition of being precisely equal to 1 013 250 dynes per square centimetre ( 101 325 Pa). It was used as a reference condition for physical and chemical properties, and was implicit in the definition of the Celsius temperature scale, which defined 100 ☌ (212 ☏) as the boiling point of water at this pressure. The standard atmosphere was originally defined as the pressure exerted by 760 mm of mercury at 0 ☌ (32 ☏) and standard gravity ( g n = 9.806 65 m/s 2). It is approximately equal to Earth's average atmospheric pressure at sea level. It is sometimes used as a reference pressure or standard pressure. The standard atmosphere (symbol: atm) is a unit of pressure defined as 101 325 Pa. For the album by Justin Jarvis, see Atmospheres (album). For the television series on the Weather Channel, see Atmospheres (TV series). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |