absolute pressure vs gauge pressure
Absolute Pressure Vs. Gauge Pressure
Force applied per unit area of any surface is called pressure. Absolute pressure refers to the measurement of pressure at absolute zero, whereas gauge pressure refers to the measurement of pressure at atmospheric pressure. Read in this Buzzle article to understand the differences between absolute and gauge pressure.
Did You Know?
Many differences exist between absolute and gauge pressure. However, same scale is used for measurement of both types.Absolute Pressure Vs. Gauge Pressure
➜ Absolute pressure is defined as the pressure measured against the zero pressure of a vacuum.
➜ Gauge pressure is defined as the pressure measured against the zero atmospheric pressure.
➜ It is cited against perfect vacuum.
➜ It is cited against the ambient air pressure.
➜ Formula for absolute pressure
Absolute Pressure = Gauge Pressure + Atmospheric Pressure
Pabs = Prel + Patm
➜ Formula for gauge pressure
Gauge Pressure = Absolute Pressure - Atmospheric Pressure
Prel = Pabs - Patm
➜ Absolute pressure is used mainly to measure pressures for aircraft's, etc.
➜ Gauge pressure is used mainly for conventional purposes.
➜ Units for measurement of absolute pressure are psia and kpaa. Wherein 'a' is the suffix given.
➜ Units for measurement of gauge pressure are barg, kPag, and psig. Wherein 'g' is the suffix given.
➜ This is the absolute value of the measured pressure.
➜ This is the relative value of the measured pressure.
➜ Absolute pressure is measured from zero (zero reference.)
➜ Gauge pressure is measured from atmospheric pressure level.
➜ Changes in atmospheric pressure doesn't affect absolute pressure.
➜ Changes in atmospheric pressure affects gauge pressure.
➜ Absolute pressure cannot be negative.
➜ Gauge pressure can be positive or negative.
➜ It is measured by using a manometer or barometer.
➜ It is measured by using a pressure gauge.
➜ Examples are altimeter, air pressure, measurement of deep vacuum pressures by scientists.
➜ Examples are measurement of blood pressure, or air pressure in vehicle tires.