- For other uses, see Pascal (disambiguation).
The pascal (symbol Pa) is the SI unit of pressure.
It is equivalent to one newton per square metre. The unit is named after Blaise Pascal, the eminent French mathematician, physicist and philosopher.
- 1 Pa
- = 1 N/m² = 1 (kg·m/s²)/m² = 1 kg/m·s²
- = 0.01 millibar
- = 0.00001 bar
Metric meteorology has long used the millibar for air pressure. On change to the preferred SI unit pascal, many meteorologists prefer to keep using the magnitude they are used to and thus do not use the preferred prefix kilo, but hecto.
- 1 hectopascal (hPa)
- = 100 Pa = 1 mbar
- 1 kilopascal (kPa)
- = 1000 Pa = 10 hPa
In the former Soviet mts system the unit of pressure is the pieze, which is equivalent to one kilopascal.
Standard atmospheric pressure is 101,325 Pa = 101.325 kPa = 1013.25 hPa = 1013.25 mbar.
The same unit is used to measure stress, Young's modulus and tensile strength.
In Unicode, Pascal is represented by ㎩, and a kilopascal is represented by ㎪.
Examples of various values (approximately)
(See SI prefix for guide to units.)
| 0.5 Pa
| Atmospheric pressure on Pluto (1988 figure; very roughly)
|
| 9.81 Pa
| The pressure caused by a depth of 1 mm of water¹
|
| 1 kPa
| Atmospheric pressure on Mars
|
| 10 kPa
| The pressure caused by a depth of 1 m of water, or
the drop in air pressure when going from sea level to 1000 m elevation¹
|
| 101,325 Pa
| Atmospheric pressure at sea level¹
|
| 10 MPa
| Pressure washer forces out water at this pressure
|
| 100 MPa
| Pressure at bottom of Mariana Trench, about 10 km under ocean¹
|
| 10 GPa
| Diamond forms
|
| 100 GPa
| Theoretical tensile strength of carbon nanotubes (CNTs)
|
¹at the Earth's surface
Comparison to other units of pressure
|
