Torr to PSI
1 torr equals 0.0193367747 pounds per square inch (rounded).
How to convert torr to pounds per square inch
To convert torr to pounds per square inch, multiply the number of torr by 0.0193367747. The factor is rounded to 10 significant digits. To go the other way, multiply pounds per square inch by 51.71493257 (rounded).
pounds per square inch = torr × 0.0193367747
Example: 10 torr = 0.193367747 pounds per square inch.
About these units
Torr (Torr)
Exactly 1/760 of a standard atmosphere (about 133.322 Pa), named after Evangelista Torricelli. Used for vacuum measurement.
In 1643 Evangelista Torricelli filled a meter-long tube, sealed at one end, with mercury and stood it in a basin of mercury. The column fell to about 76 cm and left a Torricellian vacuum above it, the first recorded creation of a permanent vacuum. In a letter dated 11 June 1644 he described living at the bottom of a sea of air, an idea that also explained why suction pumps could raise water only about 10 meters.
The torr honors him. It was originally meant to equal one millimeter of mercury at 0 degrees Celsius, but the weight of a mercury column varies with gravity, which changes with elevation and latitude. In 1954 the 10th CGPM defined the standard atmosphere as 101,325 Pa, and the torr was then fixed as exactly one 760th of that, about 133.32 Pa.
Today the torr is mostly met in high-vacuum physics and engineering. It differs from the millimeter of mercury by less than one part in seven million, so the two are interchangeable except in the most exacting work.
1 torr = 133.3223684 pascals (approximately).
Sources: Wikipedia: Torr; Wikipedia: Evangelista Torricelli; Wikipedia: Standard atmosphere (unit)
Pound Per Square Inch (psi)
About 6,894.757 pascals. The common unit for tire pressure, hydraulics and gas pipelines in the US.
Unlike most pressure units, psi has no namesake: it simply spells out its own definition, one pound-force acting on one square inch, and it is based on avoirdupois units. Used mainly in the United States, it is about 6.895 kilopascals.
The letters after the unit matter. Psia is measured against a vacuum, while psig is measured against the surrounding air, so at sea level, where the atmosphere is about 14.7 psi, you add that amount to a gauge reading to get an absolute one. A bicycle tire at 65 psig is therefore at 79.7 psia, and the label psid means a difference between two pressures rather than a reference to ambient air.
Typical automobile tires are listed at about 32 psig, and road racing bicycle tires at about 120 psig. One standard atmosphere is 14.696 psi, which gives a feel for how many multiples of sea-level air those tire pressures represent.
1 pound per square inch = 6,894.757293 pascals (approximately).
Sources: Wikipedia: Pounds per square inch; Wikipedia: Standard atmosphere (unit)
Related conversions
- PSI to torr (reverse)
- Torr to pascals
- Torr to kilopascals
- Torr to bars
- Torr to standard atmospheres
- Torr to hectopascals
- Torr to megapascals
- Torr to millibars
- Torr to millimeters of mercury
- Torr to inches of mercury
- Pascals to PSI
- Kilopascals to PSI
- Bars to PSI
- Standard atmospheres to PSI
- Hectopascals to PSI
- Megapascals to PSI
- Millibars to PSI
- Millimeters of mercury to PSI
- Inches of mercury to PSI
- Gigapascals to PSI
- Kilopounds per square inch to PSI
- Millimeters of water to PSI
See all pressure units.