What is: Barometer

A barometer is a scientific instrument used to measure atmospheric pressure. It is an essential tool in meteorology, as it helps forecast weather patterns and monitor changes in atmospheric conditions. The word “barometer” comes from the Greek words “baros,” meaning weight, and “metron,” meaning measure. Invented in the 17th century, barometers have since evolved into various types, each with its own unique features and applications.

Types of Barometers

There are several types of barometers, each designed to measure atmospheric pressure in different ways. The most common types include:

Mercury Barometer

The mercury barometer is one of the oldest and most accurate types of barometers. It consists of a glass tube filled with mercury, inverted into a dish of mercury. As the atmospheric pressure changes, the mercury level in the tube rises or falls, indicating the pressure variations. This type of barometer is often used in meteorological stations and laboratories.

Aneroid Barometer

The aneroid barometer is a more portable and compact alternative to the mercury barometer. It uses a small, flexible metal box called an aneroid cell, which expands or contracts with changes in atmospheric pressure. This movement is then translated into a reading on a dial, providing a measurement of the pressure. Aneroid barometers are commonly found in homes, offices, and on ships.

Electronic Barometer

With advancements in technology, electronic barometers have become increasingly popular. These barometers use sensors and electronic components to measure atmospheric pressure. They often come with additional features such as temperature and humidity readings, making them versatile instruments for weather monitoring. Electronic barometers are commonly used in weather stations and personal weather forecasting devices.

Applications of Barometers

Barometers have a wide range of applications beyond weather forecasting. Some of the key applications include:


Barometers play a crucial role in aviation, helping pilots determine altitude and monitor changes in atmospheric pressure during flight. This information is vital for flight safety and navigation.

Marine Navigation

Barometers are essential tools for marine navigation, allowing sailors to monitor changes in atmospheric pressure and predict weather conditions at sea. This information helps sailors make informed decisions and ensure the safety of their vessels.

Industrial Applications

Barometers are used in various industrial applications, such as monitoring pressure in manufacturing processes, controlling air pressure in cleanrooms, and ensuring the proper functioning of HVAC systems.

Historical Significance

Barometers have played a significant role in history, particularly in the field of meteorology. They have helped scientists understand weather patterns, study atmospheric phenomena, and make advancements in weather forecasting.


In conclusion, a barometer is a valuable instrument used to measure atmospheric pressure. It has evolved over time, with different types catering to various needs and applications. From the traditional mercury barometer to the modern electronic barometer, these instruments have revolutionized weather forecasting and provided valuable insights into atmospheric conditions. Whether in aviation, marine navigation, or industrial settings, barometers continue to be essential tools for monitoring and predicting changes in atmospheric pressure.