Adams, Colin Center for Space and Engineering Research, Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia.
Last reviewed:July 2016
Show previous versions
- McLeod gage
- Mechanical devices
- Pirani gage
- Ionization gages
- Knudsen gage
- Residual gas analyzer
- Links to Primary Literature
- Additional Readings
The assessment of gas pressures of lesser magnitude than standard sea-level atmospheric pressure. Vacuum measurement is important in many industries, including electronics manufacturing, metallurgy, and the pharmaceutical industry, and in the physical and life sciences. The most common unit of pressure in vacuum measurement is the torr, which is defined to be 1/760 of standard atmospheric pressure, and is approximately the pressure differential between two points separated vertically by 1 mm in a column of mercury (1 mmHg). Other units include the pascal (Pa; 1 pascal is equal to 1 newton per square meter, and 1 torr = 133.322 Pa), the atmosphere (1 atmosphere = 101,325 Pa), the bar (1 bar = 100,000 Pa), and the pound per square inch (psi; 14.696 psi = 1 atmosphere).
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information