5 Questions
Explain the physical definition of vacuum according to the American Vacuum Society in 1958.
The space filled with a gas under pressure less than 1 atmosphere, with a density of particles less than 2.5 x 10^19 particles / cm3.
What are the ranges of vacuum and their corresponding pressure values?
Low vacuum: 1 bar to 1 mbar; Medium vacuum: 1 mbar to 10^-2 mbar; High vacuum: 10^-2 mbar to 10^-7 mbar; Ultra High vacuum: 10^-7 mbar to less than 10^-14 mbar.
How is vacuum measured and what is the relationship between millibar, Torr, and Pascal units?
Vacuum is measured in millibar or Torr units. The relationship between them is 1 millibar = 0.75 torr = 100 Pa (Pascal).
In what units is atmospheric pressure measured and what is the equivalent value in millimeters of mercury?
Atmospheric pressure is measured in units of 1 bar = 1000 millibar = 760 millimeters of mercury.
Provide an example of how vacuum is naturally utilized by some animals in their lives.
Mosquitoes have a thin tube that draws blood after inserting it into the bloodstream by creating a vacuum.
Study Notes
Physical Definition of Vacuum
- The American Vacuum Society defined vacuum in 1958 as a region of space where the pressure is below atmospheric pressure.
Ranges of Vacuum and Pressure Values
- Four ranges of vacuum exist: atmosphere, low vacuum, medium vacuum, and high vacuum.
- Atmosphere: 10^5 Pa to 10^2 Pa
- Low vacuum: 10^2 Pa to 10^-1 Pa
- Medium vacuum: 10^-1 Pa to 10^-3 Pa
- High vacuum: 10^-3 Pa to 10^-7 Pa
Measuring Vacuum and Unit Conversions
- Vacuum is typically measured using a pressure gauge or vacuum gauge.
- One millibar (mbar) is equivalent to 0.75 Torr.
- One Torr is equivalent to 133.322 Pa (Pascal).
- Atmospheric pressure is typically measured in units of millibar (mbar) or Pascals (Pa).
- Atmospheric pressure is equivalent to 760 mmHg (millimeters of mercury).
Natural Utilization of Vacuum by Animals
- Certain animals, such as fish and snakes, naturally utilize vacuum in their lives.
- Fish use vacuum to respire and maintain their swim bladder pressure.
- Snakes use vacuum to facilitate the movement of their prey down their esophagus.
Test your knowledge of vacuum technology with this quiz. Explore the physical definition of vacuum and its ranges as per the American Vacuum Society. Get familiar with the key concepts and measurements related to vacuums.
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