What is a pressure gauge?
A manometer is an instrument, which is used to measure the pressure of fluids inside closed containers, such as a tank. We can find mainly two versions to measure the pressure of gas and liquids. how does a pressure gauge work
How does a pressure gauge work?
This instrument is based on the same operation of the barometer since they take the atmospheric pressure as a reference and measure the difference between the real or absolute pressure. There is the possibility of finding pressures above or below the pressure of the atmosphere. In the case of below or negative pressures, there are instruments called vacuum gauges or also called vacuum manometers.
The most frequent measurement units used in manometers are Kg / cm2, bar, Atm, Pa and Psi. how does a pressure gauge work
What is the difference between a pressure gauge and a barometer? how does a pressure gauge work
The main difference is that the barometer is used exclusively to measure atmospheric pressure and the pressure gauge is used only to measure pressure in closed containers.
Pressure gauge parts how does a pressure gauge work
Although its composition varies depending on the type that is being used, we can find some parts that are essential.
- Reception: It is responsible for transforming the force generated by pressure
- Transfer: Extends the strength of the receiving element and transmits it to the next stage
- Indication: Faces converting received force to visual indicator
Types of pressure gauges
Before talking about the types you have to know that we can find different types of classifications of the pressure gauges. such as by type of pressure, low, medium and high. We can also classify them by type of fluid to be measured, gas or liquid.
These instruments use the liquid as a measuring element, they are mainly made of a glass tube, a graduated scale and the liquid that is made up of distilled and mercury. There are three different types, U-tube, Inclined tube and inkwell or well type.
This type is used to measure the pressure difference between two points in a system
It is used to measure low pressures below 25mm.
Inkwell or well type
It is similar to the U-tube manometer, but it has some important differences. At one end it has a well in which the liquid rises or falls according to the pressure. how does a pressure gauge work
Elastic pressure gauge
This type uses the deformation of an elastic element as a means of measuring pressure. Within this category there are those of the bourdon type, diaphragm, bellows type and inclined bell.
The Bourdon manometer is possibly the most widely used pressure instrument. It is a mechanical device, which uses a metal wound in a spiral. When the pressure passes through this element, it loses curvature which is transmitted to a mechanism that moves the pressure indicator cursor. how does a pressure gauge work
It consists of a diaphragm in which pressure is exerted to cause a deformation, through a mechanism it transforms this deformation into an angular movement to indicate the pressure.
It is a kind of accordion which has the possibility of contracting and expanding depending on the pressure applied, when the bellows is stretched, a needle moves which indicates the measure. how does a pressure gauge work
Bellows – type hood bourdon
In this device a tank is used in which a fluid and a spring are placed on top. When the pressure rises the liquid rises exerting pressure on the spring.
Electronic pressure gauges
These gauges use together an LCD display, a pressure sensor and an electronic circuit to perform the measurement and display it on the visual indicator. how does a pressure gauge work