Search results
Results from the WOW.Com Content Network
The relationship between the torr and the millimeter of mercury is: 1 Torr = 0.999 999 857 533 699... mmHg; 1 mmHg = 1.000 000 142 466 321... Torr; The difference between one millimeter of mercury and one torr, as well as between one atmosphere (101.325 kPa) and 760 mmHg (101.3250144354 kPa), is less than one part in seven million (or less than ...
1 mmHg = 1 mm × 13 595.1 kg/m 3 × 9.806 65 m/s 2 = 133.322 387 415 Pa (exactly) The use of an actual column of mercury for precise measurement of pressure requires corrections for the actual gravity at given location (±0.44%) and the density of mercury at the actual temperature (−0.45% at 25 °C or 77 °F).
The tube is sealed during manufacture with the sealed end containing a vacuum. [1] Mercury is a useful material to use in a manometer because of its high density. This means that a much shorter column is needed compared to water. [2] For instance, the pressure represented by a column of 100 mm of water is just under 7.4 mm of mercury . [3]
A vacuum gauge is used to measure pressures lower than the ambient atmospheric pressure, which is set as the zero point, in negative values (for instance, −1 bar or −760 mmHg equals total vacuum). Most gauges measure pressure relative to atmospheric pressure as the zero point, so this form of reading is simply referred to as "gauge pressure".
Molecular distillation is vacuum distillation below the pressure of 0.01 torr [21] (1.3 Pa). 0.01 torr is one order of magnitude above high vacuum, where fluids are in the free molecular flow regime, i.e. the mean free path of molecules is comparable to the size of the equipment. [1]
For nearly all intents and purposes, torr is the same as mmHg. However, in most scientific journals, torr usually refers to mmHg (Absolute), (ie: 0 torr = total vacuum), whereas mmHg refers to non-absolute readings, (ie: 0 mmHg = air pressure = 760 torr. Likewise, total vacuum = -760 mmHg). So, 120/80 mmHg will usually equal 880/840 torr .
where P is the pressure of the gas, V is the volume of the gas, and k is a constant for a particular temperature and amount of gas.. Boyle's law states that when the temperature of a given mass of confined gas is constant, the product of its pressure and volume is also constant.
Dimensionless numbers (or characteristic numbers) have an important role in analyzing the behavior of fluids and their flow as well as in other transport phenomena. [1] They include the Reynolds and the Mach numbers, which describe as ratios the relative magnitude of fluid and physical system characteristics, such as density, viscosity, speed of sound, and flow speed.