Altimeter vs. Barometer — What's the Difference?

An altimeter is a device used to measure altitude, especially in aviation, by calculating the atmospheric pressure at different heights. It is crucial for pilots to determine their flying height and ensure safe navigation. On the other hand, a barometer measures atmospheric pressure to forecast weather conditions. Meteorologists use barometers to predict changes in weather by observing pressure fluctuations.

Altimeters are specifically calibrated to show altitude in feet or meters above sea level. They are essential tools in aircraft, enabling pilots to maintain desired flight levels. Barometers, however, display pressure readings in units such as millibars or inches of mercury. They are more commonly used in weather stations and by meteorologists.

While an altimeter's readings help in maintaining the correct altitude and ensuring safe flight paths, a barometer’s readings assist in predicting weather patterns. For example, a falling barometric pressure typically indicates approaching storms. Conversely, stable or rising pressure suggests fair weather.

Both devices rely on atmospheric pressure but serve distinct purposes. The altimeter adjusts its reading based on the changing pressure as altitude increases or decreases, ensuring accurate altitude measurement. The barometer, however, monitors pressure changes over time to anticipate weather changes.

An altimeter is vital in aviation for altitude measurement, whereas a barometer is crucial for weather prediction. Despite their reliance on atmospheric pressure, their applications and outputs are fundamentally different.