different scales in the world
There are several units of pressure, the use generally depends on the discipline. By the very definition of pressure, they are often defined as the ratio of a unit of force on a unit area. Unity of the international system
- The Pascal (symbol Pa) is the unit of the international system. A pressure of 1 pascal is a force of one newton exerted over an area of 1 m2: 1 Pa = 1 N / m².
- bar : 1 bar = 100 000 Pa.
- The normal atmosphere (symbol atm): 1 atm = 101 325 Pa.
- pieza is a unit derived from the meter-tonne-second system (mts) used in the former Soviet Union between 1933 and 1955: 1 pz = 1000 Pa.
- millimeter of mercury (symbol mmHg), also called torr in honor of the Italian physicist Evangelista Torricelli: 1 mmHg = 1 torr = 133.3 Pa.
- inch (or inch) of mercury (symbol inHg): 1 inHg hPa ≈ 33 86.
- millimeter of water (mmH2O), or the inch of water (cmH2O): 1 cmH2O = 98.0638 Pa.
- barye (symbol ba) is a unit of the CGS system. It is defined as one dyne per square centimeter: 1 ba 1 = dyn.cm ⁻ ² = 0.1 Pa.
- The atmosphere Technical (at symbol) or ATA: 1 at 98 = 066.5 Pa.
- psi , the English pound per square inch (PSI) is an English unit widely used particularly in hydraulics, hydraulics and hydrostatic: 1 psi = 6894 Pa.
- grams or kilograms per square centimeter (g / cm ², kg / cm ² or kgf / cm ²), often used in particle physics, by extension, to refer to a distance irrespective of the material considered (see paragraph link between pressure and distance) or altitude (the "program" or "kg" to which he refers is not the standard unit of weight, but the kilogram-force): li >
- fpa a pressure of the interstellar medium.
- 1 npa atmospheric pressure on the moon. pressure typical of a sound in water.
- uPa a pressure in a vacuum tube. pressure typical of a sound in water.
- 20 uPa the threshold of human hearing. The oscillations of the air pressure of this magnitude, at frequencies between 1 and 5 kHz, are smaller than the ear can hear a noise-free environment.
- 0.5 Pa the atmospheric pressure on Pluto (1988 figures).
- 1 Pa pressure corresponding to a force of one newton uniformly distributed over an area of one square meter. The pressure exerted by a fly standing on a postage stamp in a vacuum (globally).
- 10 Pa pressure increased by one millimeter of water column (overall). The pressure in an incandescent lamp
- 100 Pa a millibar. The threshold of pain. Sounds above this magnitude are unsustainable and may cause pain hearing, prolonged exposure can lead to hearing loss.
- 610 Pa the average atmospheric pressure on Mars to the baseline.
- 1 kPa 1% of the atmospheric pressure at sea level on Earth.
- 10 kPa pressure increased by one meter column of water 1 or the decrease in atmospheric pressure when we start from the sea level on Earth up to an elevation of 1000 m.
- 100 kPa bar.
- 101.325 kPa atmospheric pressure at sea level on Earth = 1013.25 hPa.
- 180 to 250 kPa pressure in a tire of the car.
- 407 to 607 kPa pressure in a bottle of Champagne.
- 0.8 to 2 MPa pressure used in the boilers of steam locomotives.
- 9 MPa atmospheric pressure on Venus
- 10 MPa pressure washers expel water at that pressure.
- 12 MPa pressure from a 60 kg woman wearing stiletto heels.
- 20 MPa pressure from a scuba tank aluminum.
- 100 MPa pressure at the bottom of the Mariana Trench, about 10 km below the surface of the ocean.
- 10 GPa the pressure at which diamond is formed.
- 100 GPa the theoretical yield of a carbon nanotube.
- 380 GPa pressure at the center of the earth.
- 530 TPa pressure inside a nuclear bomb like Ivy Mike.
- 6.4 PPP pressure within the detonation of a missile W80.
- 35 PPP the pressure inside the core of the Sun.
- 4.63 × 10 113 Pa pressure Planck