Six pressure measurement types include the following:
a.Absolute Pressure:
Absolute pressure is the pressure measured in reference to vacuum pressure or zero absolute. Zero absolute means total lack of pressure. Absolute pressure is denoted as ‘abs’ to differentiate it from the other types of pressure. An absolute pressure sensor is used when the measurements are affected by changes in the barometric pressure. It is also used in scenarios where it is impossible to have a pressure reference in certain ambient environments.
Some examples where absolute pressure sensors are used :
In some medical applications, where pressure measurements are affected by changes in barometric pressure.
In the case of submersible sensors, where it is difficult to obtain an external reference.
Weather stations and meteorological applications.
b.Atmospheric pressure:
Atmospheric pressure is the pressure exerted on an area due to the atmosphere. The atmosphere of the earth is heavy, and it surrounds the earth to a height of almost 500km. This pressure fluctuates depending on the weather. Low atmospheric pressure normally indicates cloudiness, high water precipitation, and wind. High atmospheric pressure indicates calm weather. It is low at higher altitudes and highest at sea level.
c.Gauge Pressure:
Gauge pressure is the measurement of the applied pressure with reference to ambient atmospheric pressure. The sensors used in gauge pressure measurements are open to environmental vagaries like humidity. Care must be taken to install these kinds of sensors in dry areas.
Gauge pressure measurements are used in measuring air pump pressure, pressure in a gas pipeline, water level measurement, hydraulic applications , and more.
d.Differential Pressure:
Differential pressure measurement is the difference between two applied pressures. One applied pressure has to be higher than the other. The reference pressure is not the ambient pressure or an internal reference pressure. The best application of differential pressure measurement is air conditioning.
e.Sealed Pressure:
Sealed pressure is the measurement of applied pressure with reference to the pressure sealed inside a chamber. The reference pressure is almost approximately 1 bar. This is done when there is no option of venting to the atmosphere. Applications are outdoor installations, industrial pressure sensors, and many high pressure applications.
f.Vacuum pressure:
Vacuum pressure is nothing but the differential pressure between atmospheric pressure and absolute pressure.
