Barometer

Barometer is an device in the study of meteorology. It is used to study atmosphere and weather phenomena. A Barometer is a scientific tool used to measure the atmospheric pressure at a specific temperature.

In this article, we will learn about barometers and their related terms including types, working principles, uses, and many more related topics.

What is a Barometer?

A barometer is a scientific device that indicates air pressure. It is used for monitoring atmospheric pressure, commonly used for weather forecasting and altitude calculations. It varies with altitude either above or below sea level. In 1643, the Italian scientist E. Torricelli discovered a scientific device named barometer. In the vacuum of barometer, mercury is used. The basic principle of a barometer relies on the balance between the weight of the air in the atmosphere and the force exerted by a column of mercury or other liquid in a vertical tube.

History of Barometer

Evangelista Torricelli, an Italian physicist and mathematician, invented the barometer for the first time in 1643. Torricelli was concerned by the problem of water pumps, that lifted water to a height of about 32 feet only. He assumed that the weight of the atmosphere was responsible for this problem.

To solve the problem, Torricelli took a large glass tube (one side open) filled with mercury, and put the opened side into a container of mercury. Surprisingly, the mercury did not completely flow out from the tube, even it stood at a height of about 30 inches. Torricelli understood that the weight of the mercury line in the tube was balanced by the weight of the atmosphere pressing down on the mercury in the container.

Torricelli’s experiment proven the existence of atmospheric pressure and also he was finding the way of measuring it. This mercury barometer, which was also called as a Torricellian tube, became the standard instrument for measuring atmospheric pressure for centuries.

How does a Barometer work?

Barometer is a glass tube that has one side open and the other side is closed. The open side of a barometer is placed in a mercury filled basin and the closed-end side is at the top. Instead of water, we normally use mercury for barometer. Because the density of mercury is more than water. The working process of a barometer is based on the balancing of mercury weight with respect to the atmospheric pressure. When the atmospheric pressure decreases, the mercury level also decreases and when the atmospheric pressure increases, the mercury level also increases. Rising the level of mercury of a barometer indicates improving weather and falling level of mercury indicates worsening weather. When the mercury level suddenly fall down, it indicates storming weather. The rising and falling level of mercury are calculated using a scale marked on the glass tube.

Types of Barometer

There are two types of barometer namely

• Mercury Barometer
• Aneroid Barometer

Mercury Barometer

The most popular barometer is the mercury barometer. Italian scientist Torricelli invented mercury barometer in 1643. It consists of a mercury-filled glass tube column and for measuring the readings, it will markings with inches on it. The top of the glass is closed and the bottom of the glass is opened and placed in a mercury-filled basin, or cistern. These barometers are gravity and environment-corrected to get accurate reading. For the reason, the more denser metal named mercury is used.

Aneroid Barometer

Aneroid barometer is made up of a combination of aneroid capsule, a thin and flexible metal box made of an alloy. This metal box is the alloy of beryllium and copper. For greater expansion and contraction of levers and springs of the box, the metal box is tightly sealed. This will happen due to a change in atmospheric pressure outside the box.

Difference between Barometer and Manometer

The basic differences between barometer and manometer are as follows:

Particulars	Barometer	Manometer
Discovered in	Barometer was discovered in 1643.	Manometer was developed in 1661.
Inventors	Evangelista Torricelli	Otto von Guericke
Measure	Barometer is used for measuring atmospheric pressure and weather forecasting.	Manometer is used for measuring a lesser or larger magnitude of pressure. It is used for measuring water pressure and gas pressure in pipelines.
Uses	It is used in smartphones for gps, altitude data transfer and for fitness apps.	It is used in power plants and research labs.

How to Make a Barometer?

To make a barometer, you have to keep in mind two things – things you have to make barometer and the procedure of making barometer.

Things you will need

The following things are needed to make a barometer:

• Permanent Marker
• Solid paper (card type)
• Straw
• Transparent Tape
• Rubber Band
• Jar/container
• Scissors
• Balloon
• pin stick/cocktail
• Glue

Procedure

• Take a balloon and cut the knot of the balloon.
• Take a rubber band to fix the cut balloon over the container by stretching it out.
• Take a straw and attach it to the balloon’s centre with the help of tape or glue and then tape a pin stick to the end.
• Take a scale and draw three lines of equal space on a solid paper with a marker. The spaces indicate low, medium and high reading.
• Tape the solid paper behind the barometer.
• Wait for few days and keep on eye on the readings according to the weather conditions.

Uses of Barometer

The uses of barometer are mentioned below:

• It is used to measure atmospheric pressure
• It is used for determining a location’s height
• Aneroid barometer is used for calibration and testing
• It is used in fluid mechanics application
• It is used for pressure measurement in aircrafts
• It is used for surface weather forecasting
• It is used to prepare Barograph
• It has many important applications in Physics, Astronomy, and Chemistry
• It is used to prepare altimeter for aircraft
• It is used in watches and mobile devices.
• It is used in meteorology and industry to predict weather.

Conclusion

In simple terms, a barometer is like a weather tool that helps us figure out how heavy the air around us is. It’s important because it tells us if the weather is likely to change soon, like if a storm is coming.

Frequently Asked Questions on Barometer

What is a Barometer?

A barometer is a kind of scientific tool used to measure atmospheric pressure at certain environment. It can show the different reading in accordance to distance, altitude.

Who invented the barometer and in which year?

Italian scientist Evangelista Torricelli invented the atmospheric pressure measurement device named barometer in the year 1643.

How many types of barometers are there?

There are two categories of barometer found namely:

1. Mercury Barometer
2. Aneroid Barometer

How does a barometer work?

A barometer works on the principal of balancing of mercury weight. It will react according to the atmospheric pressure.

What is 1 atm pressure in torr?

1 atm pressure = 760 torr.