What instrument is primarily used to gauge atmospheric pressure?

The barometer is the instrument specifically designed to measure atmospheric pressure. It operates on the principle of detecting the weight of the atmosphere pressing down on a specific area. In aviation and meteorology, barometers are crucial for understanding weather patterns and altitudes. They help pilots determine altitude by relating pressure changes to height variations and are essential in weather forecasting, as changes in atmospheric pressure can indicate incoming weather systems.

While altimeters are closely related to barometers, they are specifically calibrated to provide altitude information based on atmospheric pressure readings. Thermometers measure temperature, and anemometers are used to gauge wind speed, demonstrating that each instrument serves distinct functions unrelated to atmospheric pressure measurement. This distinction highlights the barometer's unique role in meteorological and aviation contexts.