A barometer is a scientific instrument which is used to measure atmospheric pressure. It is the force exerted by the weight of the air in the earth’s atmosphere. Atmospheric pressure varies with weather patterns and altitude, making a tool for telling changes in the weather. It is useful for calculating shifts in air pressure that can show upcoming weather systems, such as high-pressure that may include fair weather or low-pressure stormy weather areas. The operation depends on the principle that the weight of the air above us creates pressure on the Earth’s surface. This pressure is calculated in various units, such as millibars (mb) or inches of mercury (in Hg).


When was barometer invented?

This was invented in the early 17th century. Evangelists Torricelli was an Italian physicist and mathematician. He invented the first mercury barometer in 1643.His creation was pivotal moment in the history of science and meteorology. This contains a long glass tube filled with mercury, switched into a dish of mercury. As atmospheric pressure changes, the height of the mercury column in the tube changes. Torricelli’s invention show the relationship between variations in atmospheric pressure and the height of the mercury column, leading to the discovery of the principles underlying barometric measurements.

The discovery of the barometer was a main step forward to figure out the properties of the Earth’s atmosphere and provided the way for advances in meteorology, weather telling, and the study of air pressure and its affect on weather patterns. 

Types of barometer

There are various types o, each designed to measure atmospheric pressure using different principles and methods. Here are some common types :

Types of barometer

  • Mercury Barometer: This is the traditional type invented by Evangelists Torricelli. It  contains a glass tube filled with mercury, put in a dish of mercury. Changes in atmospheric pressure cause the mercury column to rise or fall, providing a direct measurement of pressure. 
  • Aneroid Barometer: This type uses a flexible metal chamber (aneroid cell) that expands and contracts with changes in atmospheric pressure. As the cell changes shape, it has a mechanical linkage that is connected to a pointer on a dial, showing the pressure. These are solid, moveable, and commonly found in homes and weather stations.
  • Digital Barometer: This type has electronic sensors to calculate atmospheric pressure. The sensor converts pressure changes into electrical signals, which are then shown digitally on a screen. These often provide extra information such as temperature, humidity, and weather forecasts.
  • Barograph Barometer: A barograph is a recording barometer that continuously records the changes that occurs in atmospheric pressure on a rotating drum or chart. It provides a graphical representation of pressure trends over time, allowing for explained analysis of weather patterns.
  • Water Barometer: This type uses the principles of hydrostatic pressure. It consists of a U-shaped tube filled with water, with one end open to the atmosphere. Changes in atmospheric pressure cause the water level in the tube to rise or fall, and the height difference is used to calculate the pressure.
  • Fortin Barometer: This was named after Jean Fortin. This is a mercury barometer with a  vernier scale for small readings. It includes adjustments for temperature and altitude to increase accuracy.
  • Barocyclometer: It is also known as a cyclone barometer, this is designed to show the approach of cyclones or low-pressure systems. It measures the rate of change of atmospheric pressure, which can indicate the likelihood of stormy weather.
  • Micro Barograph: This is a highly sensitive barograph that can find even small changes in atmospheric pressure. It is used for scientific research and monitoring earthquake activities. These are just a few examples of the types available. Each type has its advantages and applications, providing different needs in meteorology, research, navigation, and personal use.

Applications of barometer

Barometers have a vast range of applications in various fields due to their capacity to measure atmospheric pressure, which provides valuable information about weather patterns, altitude changes, and more. Here are some common applications :

Applications of barometer

  1.  Weather Forecast and Meteorology: Barometers are widely used in meteorology to check changes in atmospheric pressure, which helps in finding weather patterns, identify approaching high-pressure or low-pressure systems, and count on changes in weather conditions.
  2. Aviation and Navigation: Pilots and navigators use barometric readings to find altitude and make flight adjustments. Barometric pressure measurements helps in setting altimeters and providing critical information for safe air travel.
  3. Marine Navigation: It play a critical role in marine navigation by showing variations in atmospheric pressure, which can help sailors predict shifts in weather and make sensible decisions for safer navigation.
  4. Altitude Measurement: These are used to calculate altitude changes, especially in mountainous regions or during outdoor activities like hiking, trekking, and mountaineering.
  5. Weather Stations and Forecasting: Barometric data collected from various locations contribute to weather forecasting models and help meteorologists make exact predictions about local and regional weather conditions.
  6. Climate Studies: Long-term barometric measurements provide data for climate studies, helping researchers predict long-term atmospheric trends and their impression on climate change.
  7. Air Pressure Studies: They are used in atmospheric research to study changes in air pressure and their effects on weather phenomena, air circulation, and climate gestures.
  8. Critical  Weather Detection: Increase drops in atmospheric pressure often signal the approach of severe weather events like storms, hurricanes, and  tropical typhoons. Barometers help in early detection and preparation.
  9. Industrial Processes: In some industrial processes, barometers are used to find pressure variations within systems, making sure efficient and safe operations.
  10. Health and Medical Applications: Barometric readings can be used to estimate variations in atmospheric pressure, which may affects individuals with certain health conditions, such as migraines or joint pain.
  11. Educational Demonstrations: These are used in educational institutes to teach students about atmospheric pressure, weather patterns, and important principles of forecast.
  12. Research and Scientific Studies: They are important tools for scientific research in fields such as geology, oceanography, and environmental science, where atmospheric pressure variations can effect various phenomena.
  13. Historical and Cultural Significance: They have historical importance as instruments that transforms our understanding of atmospheric pressure and weather prediction. They are also used as decorative and functional items in homes.

 How to make barometer?

Making a simple barometer at home can be a easy. Here is a guide on how to make a home-made barometer using available materials:

 How to make barometer?

Materials Needed:

  • A glass jar or plastic bottle with a large mouth
  • An elastic drinking straw
  • Modelling clay 
  • A small piece of hint card or heavy paper
  • A ruler or measuring tape
  • Clear tape
  • A small container of water


  1. Ready the Jar:
  • Take the glass jar or plastic bottle and fill it about one third full with water.
  • If using a plastic bottle, you can cut off the top portion to create a larger mouth.
  1. Make the Barometer Column:
  • Take the flexible drinking straw and fill it half with water from a small container.
  • Cover both ends of the straw with modelling clay to prevent water from wasting.
  1. Built the Barometer:
  • Put one end of the straw into the water filled jar, make sure that the covered end of the straw is above the water level.
  • Attach the other end of the straw to the outside of the jar using clear tape in vertical position.
  1. Create the Scale:
  •  Cut a small piece of hint card or heavy paper and create a scale using a ruler or measuring tape.
  • Mark the scale with equal addition, such as millibars or inches of mercury, and mark the values.

Observation and Use:

  1.  As atmospheric pressure varies, it will put different forces on the water in the jar and the snared air in the straw.
  2.  The water level in the straw will rise or fall accordingly, indicating changes in pressure.
  3. Check the position of the water level in the straw relative to the scale ,to make observations about variations in pressure and potential weather changes.

Elevate your expertise of using barometer by reading our article on How to measure air speed and air pressure effectively

FAQ’s about barometer

What is a barometer?

It is a scientific instrument that is used to calculate atmospheric pressure, which provides awareness about weather patterns and changes.

How does a barometer work?

These are based on the principle that variations in atmospheric pressure affect the height of a column of liquid  or the movement of an elastic chamber (aneroid cell), which is then changed into a pressure reading.

What is atmospheric pressure and when it decreases?

Atmospheric pressure is the force exerted by the weight of the air in Earth’s atmosphere. It decreases with increasing altitude.

What are the units of measurement for atmospheric pressure?

Atmospheric pressure is often measured in units such as millibars (mb) or inches of mercury (in Hg).

What are the different types of barometers?

Common types include mercury , aneroid , digital , barograph, water barometers, and special types like Barocyclonometer.

Why is atmospheric pressure necessary?

Atmospheric pressure affects weather patterns, wind circulation, and air density, which in turn effect weather forecasts and navigation.

How can barometric pressure tells about changes in weather ?

Increased drops in barometric pressure often indicate the low-pressure systems and stormy weather, while rising pressure indicates fair conditions.

Are there moveable barometers?

Yes, there are portable and hand-held barometers used for outdoor activities like hiking, where altitude variations are important.

Can barometers be used for altitude measurement?

 Yes, changes in atmospheric pressure can be used to find changes in altitude, which is useful in mountainous regions.

How accurate are barometers?

The accuracy of barometers depends on the type and quality of the instrument. Modern digital one tend to offer high accuracy.

Are there digital barometers available?

Yes, digital ones use electronic sensors to measure pressure and provide some extra features like temperature readings and weather forecasts.

Can barometers be used for climate studies?

Yes, long-term barometric data contributes to climate studies by providing insights into atmospheric trends and variations.

Do barometric pressure changes affect health?

Some individuals with certain health conditions, like migraines or joint pain, may be sensitive to changes in barometric pressure.

How do I balance a barometer?

Calibration involves adjusting a barometer to make sure its accuracy. This can be done using known reference pressures or by following manufacturer guidelines.

Can I use a barometer to find specific weather events?

Barometric pressure changes can provide general indications of weather systems, but they may not predict specific events with high accuracy.

Are barometers used in industries other than meteorology?

Yes, they have applications in aviation, navigation, research, industrial processes, and more. If you want to purchase barometer then you can buy it from amazon.

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