Pièzes to Standard Atmospheres (pz to atm)
1 pièze equals 0.009869232667 standard atmospheres (rounded).
How to convert pièzes to standard atmospheres
To convert pièzes to standard atmospheres, multiply the number of pièzes by 0.009869232667. The factor is rounded to 10 significant digits. To go the other way, multiply standard atmospheres by 101.325.
standard atmospheres = pièzes × 0.009869232667
Example: 10 pièzes = 0.09869232667 standard atmospheres.
About these units
Pièze (pz)
Exactly 1,000 pascals (1 kPa): the pressure unit of the old French meter-tonne-second (MTS) system.
French metrologists coined the pièze, symbol pz, for pressure in the metre-tonne-second (MTS) system, which was France's legal system from 1919 to 1961. The Soviet Union adopted the same system in 1933 and abolished it in 1955. The name is French, and Wikipedia does not explain its origin further.
The MTS system used large units suited to industry rather than laboratories, and the pièze follows that pattern. It is defined as one sthène of force per square metre, which works out to exactly 1,000 pascals, or one kilopascal. That is the same as 10 millibars or one centibar, about 7.5 torr, and roughly 0.145 pounds per square inch.
Compared with everyday pressures, one pièze is about one hundredth of standard atmospheric pressure, so steam boilers and hydraulic machinery of the period would be quoted in tens or hundreds of pièzes. The unit disappeared with the MTS system, and the kilopascal now fills the same role.
1 pièze = 1,000 pascals (exactly).
Sources: Wikipedia: Pièze; Wikipedia: Metre-tonne-second system of units
Standard Atmosphere (atm)
Exactly 101,325 pascals, the average pressure of the atmosphere at sea level.
A column of mercury about 76 cm tall was Torricelli's measure of the air, and the standard atmosphere began as exactly that: the pressure of 760 mm of mercury at 0 degrees Celsius under standard gravity. It was used as a reference for physical and chemical properties, and the Celsius scale set 100 degrees as the boiling point of water at that pressure.
In 1954 the 10th CGPM confirmed the standard atmosphere as exactly 1,013,250 dynes per square centimeter, which is 101,325 pascals, a definition that no longer depends on the properties of any substance.
In practice one atmosphere is about 1.01325 bar, 760 mmHg, 14.696 psi or 29.92 inHg, and roughly the pressure of 10.33 meters of water. Chemistry splits on it: until 1982 standard temperature and pressure used 1 atm, but that year IUPAC recommended a standard pressure of exactly 100 kPa instead.
1 standard atmosphere = 101,325 pascals (exactly).
Sources: Wikipedia: Standard atmosphere (unit); Wikipedia: Atmospheric pressure; Wikipedia: Evangelista Torricelli
Related conversions
- Standard atmospheres to pièzes (reverse)
- Pièzes to pascals
- Pièzes to kilopascals
- Pièzes to bars
- Pièzes to PSI
- Pascals to standard atmospheres
- Kilopascals to standard atmospheres
- Bars to standard atmospheres
- PSI to standard atmospheres
- Hectopascals to standard atmospheres
- Megapascals to standard atmospheres
- Millibars to standard atmospheres
- Torr to standard atmospheres
- Millimeters of mercury to standard atmospheres
- Inches of mercury to standard atmospheres
- Gigapascals to standard atmospheres
- Kilopounds per square inch to standard atmospheres
See all pressure units.