Barometer

A barometer is a scientific instrument used to measure atmospheric pressure. It is an important tool in weather forecasting and is used to monitor changes in air pressure. There are two main types of barometers: mercury barometers and aneroid barometers.

Mercury Barometer

A mercury barometer consists of a long glass tube filled with mercury, with one end submerged in a mercury-filled reservoir. The height of the mercury in the tube changes with variations in atmospheric pressure. As the atmospheric pressure increases, the mercury in the tube rises, and as the pressure decreases, the mercury falls. The height of the mercury column is a measure of the atmospheric pressure at that location.

Aneroid Barometer

An aneroid barometer uses a small, flexible metal box called an aneroid cell. This cell is sensitive to changes in air pressure, and as the pressure changes, it causes the cell to expand or contract. These changes are then converted into a mechanical movement that is displayed on the barometer's dial. Aneroid barometers are often used in homes and offices as a more portable and safe alternative to mercury barometers.