# Pressure Pressure = Force / Area.

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Pressure Pressure = Force / Area

Barometer faculty.uncfsu.edu/dautrey/CHEM%20140/chapter10-notes.ppt

] faculty.uncfsu.edu/dautrey/CHEM%20140/chapter10-notes.ppt

Manometer U-tube Manometer
Courtesy Christy Johannesson

Manometer

Barometer

Manometer Higanyos manométer: U.S. National Chemistry Olympiad 1995 National Test An open-ended mercury manometer is used to measure the pressure exerted by a trapped gas as shown in the figure. Atmospheric pressure is 749 mmHg. What is the pressure of the trapped gas?

Pressure Conversions 1 atmosphere (atm) 760 mm of Mercury (mm Hg)
760 torr Pascal (Pa) Kilopascal (kPa) 14.7 pounds per square inch (psi) 29.92 inches of Mercury (in Hg)

Manometer

What does it do - Principles
Manometers What does it do - Principles a b c Monitoring Equipment We will go through the principles of a manometer. Starting with figure a. Here, the manometer is in its simplest form. It is a U-tube about half filled with liquid. With both ends of the tube open, the liquid is at the same height in each leg. In figure b you can see that when positive pressure is applied to one leg, the liquid is forced down in that leg and up in the other. The difference in height, "h," which is the sum of the readings above and below zero, indicates the pressure. Figure c shows that when a vacuum is applied to one leg, the liquid rises in that leg and falls in the other. The difference in height, "h," which is the sum of the readings above and below zero, indicates the amount of vacuum. h h Source: Dwyer Instruments, © UNEP 2006