what is a barometer

A barometer is a scientific instrument used to measure air pressure in a specific environment. It is an essential tool for weather forecasters and scientists, as pressure tendency can forecast short-term changes in the weather. There are two main types of barometers: mercury and aneroid. A mercury barometer uses a column of mercury to measure atmospheric pressure, while an aneroid barometer uses a flexible-walled evacuated capsule that deflects with changes in atmospheric pressure. Barometers can also be used to measure altitude, and they are crucial for predicting weather patterns and extreme weather events. Changes in air pressure, as measured with barometers, can predict short-term changes in the weather, making barometers an important tool for monitoring and forecasting weather conditions.