Absolute pressure

Absolute pressure is a measure of the total pressure in a system, including both the atmospheric pressure and the gauge pressure. It is often used in thermodynamics, fluid dynamics, and other scientific and engineering fields.

Definition

Absolute pressure is defined as the sum of the atmospheric pressure and the gauge pressure. The gauge pressure is the pressure measured relative to the ambient atmospheric pressure. In other words, absolute pressure is the pressure relative to a perfect vacuum (zero pressure).

Measurement

Absolute pressure is typically measured in units of force per unit area, such as pascals (Pa), pound-force per square inch (psi), or bars. It can be measured using a variety of instruments, including manometers, barometers, and pressure sensors.

Applications

Absolute pressure is used in a wide range of applications. In thermodynamics, it is used to calculate the enthalpy and entropy of a system. In fluid dynamics, it is used to calculate the Bernoulli equation and other fluid flow equations. In engineering, it is used in the design of pressure vessels, pumps, and turbines.

See also

• Pressure measurement
• Atmospheric pressure
• Gauge pressure
• Vacuum