Høydemåleren

Høydemåleren, or altimeter in English, is an instrument used to measure altitude. It works by sensing atmospheric pressure, which decreases with increasing altitude. There are two main types of altimeters: aneroid and barometric.

Aneroid altimeters use a sealed metal chamber, called an aneroid capsule, that expands or contracts in response to changes in atmospheric pressure. This movement is then translated into an altitude reading on a dial. Barometric altimeters are similar but often use a more sophisticated mechanism for greater accuracy.

These instruments are crucial in aviation for pilots to determine their height above sea level, which is essential for navigation, air traffic control, and maintaining safe separation between aircraft. They are also used in mountaineering, hiking, and by paragliders and hang gliders to monitor their ascent and descent.

Modern altimeters often incorporate digital technology and can be integrated into GPS systems, providing more precise and versatile altitude data. Calibration is important for accurate readings, as atmospheric pressure can be affected by weather conditions. Despite the advent of GPS, mechanical altimeters remain a vital backup system in many aircraft.