In vacuum technology and process engineering, pressure measurement is critical for system integrity and performance. The Torr is a non-SI unit of pressure, defined as exactly \(1/760\) of a standard atmosphere. It is named after Evangelista Torricelli, the inventor of the mercury barometer. One Torr is approximately equal to one millimeter of mercury (mmHg).
The Pascal (Pa) is the SI derived unit of pressure, defined as one newton per square meter (\(1 \text{ N/m}^2\)). It is the standard unit used in scientific and industrial calculations globally.
Torr Applications: Primarily used in high-vacuum systems, such as mass spectrometry, semiconductor manufacturing, and thin-film deposition.
Pascal Applications: Used in general engineering, fluid mechanics, structural analysis, and international scientific reporting.
To convert between these units, we use the conversion factor \(1 \text{ Torr} \approx 133.3224 \text{ Pa}\).
Torr to Pascal Conversion Reference Table
Torr (Torr)
Pascal (Pa)
0.1
13.3322
0.5
66.6612
1.0
133.3224
2.0
266.6448
5.0
666.612
10.0
1333.224
20.0
2666.448
50.0
6666.12
100.0
13332.24
500.0
66661.2
1000.0
133322.4
Conversion Example: 10 Torr to Pascal
To convert a pressure value from Torr to Pascal, multiply the Torr value by the conversion factor of 133.3224.
The Torr remains a standard in vacuum technology because many legacy gauges and vacuum pumps were calibrated in Torr or mmHg. It provides a convenient scale for high-vacuum ranges where Pascal values would involve very large exponents.
For most practical engineering purposes, yes. However, strictly speaking, 1 Torr is defined as \(1/760\) of a standard atmosphere, while 1 mmHg is the pressure exerted by a 1 mm column of mercury at a specific density and gravity. The difference is negligible for standard industrial applications.
"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)