Definition and Function of Barometer

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Definition and Function of Barometer – Barometer Is ? Here are the Definitions, Functions, Types, Units and how the barometer works complete with sample images

When checking the weather forecast, you will probably find one info which is air pressure. This is a component that affects the wind, that is, the air moves due to the difference in pressure.

Experts use a special tool that is a barometer to make these measurements. Briefly, a barometer is a type of measuring instrument that is able to determine the value of free air pressure. In detail we will review below.

What is a Barometer?


The definition of a barometer is a measuring instrument used to measure the pressure of the earth’s air and atmosphere. The word barometer comes from the Greek “Baros” (weight) and “Metron” (Size).

Generally, this barometer measurement instrument is often used for reference in analyzing weather changes in the near future and is also sometimes used to measure the height of mountaineers.

You need to know, this tool works similarly to a thermometer but the scale reference is different. In addition, configurations and components are also more complex because they have to measure pressure with high accuracy.

One thing to know is outdoor use. To measure the pressure in the room, there is another version of the barometer that is often used on pumps or machines.

The parts of the barometer adjust to their type. There is a barometer using mercury and water as a scale reference. The components consist of a scale, a tube, mercury, and a part connected to the pressure.

There are also those who use metal so that they require certain metal components that are sensitive to pressure changes. You can see more details about the types of barometers and the functions of the barometers in the review below.

Unit Barometer

The unit of barometer according to SI (International Units) is Pascals (Pa). But related to the type of measurement, sometimes the barometer also uses millibars (mb), inches of Mercury (inHg), and also Atmospheres (Atm) units.

However, to make a determination between the two units, the formula is: 29.92 inHg = 1.0 Atm = 101325 Pa = 1013.25 mb. The table below will describe the units of barometers that exist around the world.

Unit Barometer Application
Pascals (Pa) Origin of the International Unit (SI) of Air Pressure
Millibars (mb) Meteorological Agency Measurement Units
Atmospheres (Atm) Air pressure at sea level at 59 °F (15 °C)
Inches of Mercury (inHg) Commonly used in the United States

Barometer Function


The main function of the barometer is as a tool to measure the pressure of the earth’s air and atmosphere. In addition to these main functions, the barometer has other functions in the Meteorology, Science &Research, and various other industries. Here’s the review:

  • Meteorology &Geophysics Sector (BMKG)

The main function of the barometer is in the field of meteorology. Air pressure should be available as data in the weather forecast. This info is useful for determining the direction of wind and rain.

  • Air transport

Air transport such as aircraft provides a barometer that is directly installed in the control panel system. You need to know, the air gets thinner and the pressure decreases when it is at an altitude. Therefore, these sensors must show an accurate position as part of the security.

  • Science and research

The barometer is also useful for researchers. They use it when they need data related to air pressure. The data will be used as a research reference so that it is useful for science.

  • Smartphone Industry

The latest smartphones have an air pressure gauge component. You use this sensor to check the surrounding conditions. In general, sensors are part of a temperature measuring device and then other features are developed to get additional info.

  • Mountaineering

Another function of the barometer is that it can be used to measure the height of climbers from sea level. This tool has a big role for mountaineers and researchers who want to know what their height points are.

Types of Barometer Types


As we all know that the barometer is a device for measuring the pressure of the earth’s air and atmosphere. This tool has been around for hundreds of years and the first version was invented by a scientist who invented a barometer named Torricelli which was later refined by Galileo to have higher accuracy.

Currently, barometer type types are available with different components but the purpose remains the same which is to measure air pressure. Check out the following list for further explanation.

  • Mercury Barometer

Mercury is often used to measure various air-related variables such as temperature and pressure. Mercury barometers have tubes and scales as well as mercury materials that move up and down according to local conditions.

The use of this tool is also easy and more practical. Mercury was chosen because it has a high boiling point so that it does not break and evaporate. In addition, the freezing point is also very low to avoid freezing when taking measurements in extremely cold temperatures.

  • Barometer Air

The water barometer uses a liquid that is in two different parts. When the pressure in one of them rises or falls, the water will fill or actually decrease so that it appears to be of a certain scale. This tool is often used for quick and practical pressure check purposes.

  • Barometer Aneroid

The other type is to use metals called aneroids. This barometer consists of two metals that will move and change as the pressure rises or falls. Next, you look at the scale and find out directly what the current air pressure value is.

  • Barometer Barograf

Furthermore, another type of barometer is the barograph. The components are similar to the previous tool but there is a kind of feature for note-taking. This tool will write down the latest situation of the pressure on a certain period.

  • Barometer Digital

The latest and more advanced barometer tool is the digital ver. You don’t need to calibrate often because digital technology has high accuracy. In addition, the calculations and info provided are also clearer.

You see the latest air pressure results from the LED display. Some digital tools like this also add features such as thermometers so that the info is more complete.

Read Also Definition and Function of Voltmeter

How the Barometer Works


The next discussion is how the barometer works which is quite complicated. When wearing mercury type, you need to place it in an open space so that it is exposed to air directly.

Next, check the changes of the mercury scale until it stops in the range of the figure. With the same system, a metal barometer also determines the scale of direct air exposure.

How to use a barometer is not difficult because this tool will work automatically similar to a thermometer. If you use the digital version, you don’t need to bother specifying settings.

Pressure values and other info will appear on the LED screen. In addition, there are also tools capable of measuring several variables such as pressure, temperature, and humidity.

How To Use Barometer For Weather Forecast :

  • How to predict the weather forecast using a barometer is more or less like this. The results of high pressure measurements in the atmosphere generally indicate that today’s forecast will experience sunny weather.
  • Meanwhile, if there is a change in atmospheric pressure that becomes low, it is expected that there will be cloudy, rainy, and it can also be until there is a storm.
  • The low pressure that exists in this atmosphere usually goes hand in hand with the arrival of rain. Between these two conditions, the barometer will usually undergo a system of changing readings.

If you want to have this weather measurement instrument, you need to know that the price of the barometer adjusts to the type and size. For regular use, you’d better choose the digital version as it proves to be safer and easier.

In addition, how to use the barometer is also not difficult. Since tools like this are not always used, the price is relatively stable and quite affordable. So the price barometer is varied and make sure to buy as needed.


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