2.WATER SUPPLY NOTES CONTINUED_backup.pdf

1. WATER SUPPLY NOTES ………………CONTINUATION FROM PROPERTIES
OF LIQUIDS
TYPES OF PRESSURE
A. Absolute Pressure
B. Atmospheric pressure
C. Gauge pressure
D. Vacuum pressure
A.Absolute Pressure
Absolute pressure is the pressure measured relative to a perfect vacuum, with zero pressure being
defined as absolute zero pressure. It is expressed in units of force per unit area, such as Pascals
(Pa).
B.Atmospheric pressure
Atmospheric pressure is the pressure exerted by the weight of the atmospheric air on the surface
of the objects in contact. Also known as barometric pressure.
C.Gauge pressure
Gauge pressure is a type of pressure measurement that is relative to atmospheric pressure in which
atmospheric pressure is taken as datum. It is expressed in units of force per unit area, such as Pascals
(Pa).
D.Vacuum pressure
Its defined as the pressure below the atmospheric pressure. A vacuum is a region of space with a
pressure that is lower than atmospheric pressure. In many industrial and scientific applications,
vacuums are created using vacuum pumps, which remove air from a sealed chamber to create a
low-pressure environment. Vacuum pressure is often used in manufacturing processes, such as
vacuum coating and vacuum packaging, as well as in scientific experiments, such as particle
physics and space research. Vacuum pressure is typically measured relative to atmospheric
pressure and is expressed as a negative value.