In vacuum technology and industrial process engineering, pressure measurement is critical for system integrity. The Torr is a non-SI unit of pressure defined as exactly \(1/760\) of a standard atmosphere. It is named after Evangelista Torricelli and is widely used in high-vacuum applications, such as semiconductor manufacturing and mass spectrometry.
The Pound per square inch (psi) is a unit of pressure based on avoirdupois units, commonly used in the United States for industrial hydraulics, pneumatic systems, and tire pressure monitoring. While Torr is preferred for sub-atmospheric measurements, psi is the standard for positive pressure systems.
Torr: Essential for measuring vacuum levels where precision in low-pressure environments is required.
psi: The standard for mechanical engineering, fluid power, and structural pressure testing.
To convert between these units, we utilize the conversion factor \(1 \text{ Torr} \approx 0.0193368 \text{ psi}\).
Torr to Pound per square inch Conversion Reference Table
Torr (Torr)
Pound per square inch (psi)
0.1
0.0019
0.5
0.0097
1.0
0.0193
2.0
0.0387
5.0
0.0967
10.0
0.1934
20.0
0.3867
50.0
0.9668
100.0
1.9337
500.0
9.6684
1000.0
19.3368
Conversion Example: 10 Torr to psi
To convert a pressure value from Torr to psi, multiply the Torr value by the conversion factor of \(0.019336780106971138\).
Torr is preferred in vacuum science because it provides a more granular scale for sub-atmospheric pressures. Since 1 psi is equivalent to approximately 51.7 Torr, using psi for high-vacuum measurements would result in inconveniently small decimal values.
Yes, the conversion factor is derived from the definition of standard atmospheric pressure (101,325 Pa). Since both Torr and psi are defined relative to standard atmospheric pressure, the ratio remains constant for all engineering calculations.
"On fait la science avec des faits, comme on fait une maison avec des pierres ; mais une accumulation de faits n'est pas plus une science qu'un tas de pierres n'est une maison." "Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house." — Henri Poincaré (French Mathematician, Theoretical Physicist & Mining Engineer)