Measurement of Fluid Pressure

Fluid pressure is measured using liquid columns in tubes, either vertically or at an inclination, termed manometers. The height of the liquid column determines the pressure difference.

The simplest manometer is a piezometer tube used to measure pressure. It is a vertical tube open at the top and connected to a container, using the same fluid to indicate the pressure in the tube.

Another commonly used manometer is the U-tube manometer, which consists of a U-shaped tube connected to the fluid source. It contains a different fluid, called the gauge fluid, which does not mix with the fluid whose pressure is being measured.

The inclined-tube manometer has one leg inclined, containing gauge fluid that does not mix with the measured fluid, and the pressure difference is read along the incline for increased sensitivity.

U-tube and inclined-tube manometers are commonly used to measure the pressure difference between two containers or points within a system.

Other pressure gauges include the Bourdon gauge, which measures the pressure of fluids or gases, and the aneroid barometer, which measures atmospheric pressure.