Types Of Pressure
We can easily classified pressure into different categories that include,
- Absolute Pressure
- Gauge Pressure
- Differential Pressure
- Sealed Pressure or Vacuum Pressure
There are different types of Pressure, and they have different units of pressure. For instance, atm is the unit used for atmospheric pressure. Let’s take a look at the different types of Pressure present,
Ambient Pressure
It is defined as the pressure applied to an object because of its surroundings including liquid, gases, and other variables.
Atmospheric Pressure
Air is present above the sea level, the pressure exerted by the air in the atmosphere is known as atmospheric pressure. The unit used for measuring the atmospheric pressure is atm.
The human body also has Pressure inside the body which compensates for the pressure present in the atmosphere, Therefore, the Human body does not feel it. The atmospheric pressure varies due to the fluctuation in the atmosphere. The weight of air is responsible for the atmospheric pressure, and it is essential for life on Earth.
The instrument used to measure the atmospheric pressure is called Barometer. Barometer has Mercury filled, and it is vacuumed in the rest of the space. It measures Patm as pgh.
Patm = pgh
Where,
- p is the density of the air
- g is the acceleration due to gravity
- h is the height of the mercury
Absolute Pressure
Absolute Pressure is the pressure with respect to Zero pressure present, that is, with respect to no pressure present in the empty, free space. No pressure is obtained in a vacuum. Absolute pressure is denoted as Pabs
Differential Pressure
Differential Pressure, as the name suggests, is the difference between the two values of pressure. The pressure obtained will be lesser than either of the pressures and the unit is the same for the differential pressure obtained.
Pd = P2 – P1
Gauge Pressure
Gauge pressure is also known as Overpressure, and it is the recently invented pressure. The differential pressure obtained from atmospheric pressure and absolute pressure is known as overpressure or gauge pressure.
Below given figure shows the particular relation among Gauge Pressure, Absolute Pressure, Atmospheric pressure,
Note: In order to measure Blood pressure, an inflatable cuff is placed on the forearm, Blood flow is detected and the corresponding pressures are measured in the mercury- filled manometer (Device used to measure pressure). The maximum blood pressure is called as Systolic Pressure. The minimum blood pressure is called as Diastolic pressure.
Sealed Pressure
The vacuum is a space where the absolute pressure is zero. Perfect vacuum condition is difficult to achieve practically and is only a theoretical value. When the pressure is lower than the atmospheric pressure vacuum is created. Practically, the vacuum will only be partially achieved and is known as the partial vacuum. A high vacuum means that the absolute pressure is very low.
The pressure is measured with reference to a sealed chamber closed with atmospheric pressure. The sealed sensor is used to measure the sealed pressure and is made of a sensing element that is sealed to make it air-tight and avoid further changes in the pressure due to changes in atmospheric conditions. Sealed pressure is used to protect pressure transducers from damage.
Vacuum Pressure
The pressure which is calculated below the atmospheric pressure is known as vacuum pressure. Hence, the negative value of the gauge pressure is the vacuum pressure.
Read More,
Types of Pressure
Pressure is the force applied per unit area of an object. It is also called the per unit force on an Area. There are various types of pressure that we encounter in our daily life including atmospheric pressure, Gauge pressure, etc. Pressure is calculated by taking the ratio of the force applied to the surface area of the object.
In this article, pressure, its formula, its types, and others are in detail.