Gases: Pressure
Terms
Atmosphere
-
A unit of measurement defined as 101,325 Pascals. The typical pressure
at sea level varies around one standard atmosphere (atm). Atmospheric
pressure
P
can be calculated via the following equation:
| P = ghρ |
Bar
-
A unit of measurement equivalent to
1×105
Pascals.
Barometer
-
A device used to measure atmospheric pressure.
Barometers.
mm Hg
-
A unit of pressure commonly used with the barometer. It corresponds to 1
torr and 1/760 atm at 0
o
Celsius only.
Pascal
-
The SI unit of pressure. 1 Pascal =
1 N/m2
.
Pounds per Square Inch
-
A unit of pressure commonly used in the United States. 1 psi =
1 lb
in-2
. 14.6960 psi corresponds to one atmosphere.
Pressure
-
Pressure = Force/Area. The standard atmospheric pressure is 101,325 Pascals.
Torr
-
A unit of pressure closely related to mm Hg, but more convenient and
absolute. 1 Torr = 1 mm Hg at 0
o
Celsius. 1 Torr always equals 1/760
atm, irrespective of the temperature.
