What is the purpose of the Kollsmann window on an altimeter?

The purpose of the Kollsmann window on an altimeter is to change the pressure setting, which is critical for accurate altitude readings. An altimeter measures the atmospheric pressure and converts this pressure into altitude. The pressure at a given altitude can fluctuate due to weather conditions; therefore, pilots must adjust the altimeter to local atmospheric pressure to ensure the readings reflect the true altitude of the aircraft.

The Kollsmann window allows the pilot to input the current altimeter setting, typically provided by air traffic control or taken from weather reports. This ensures that the altimeter provides a precise altitude reading above sea level, which is crucial for safe navigation and operation of the aircraft.

While the altimeter does display altitude in feet, calibrating it and measuring temperature relate to different functions that do not involve the Kollsmann window directly. Calibration is part of the overall setup and function of the altimeter, but the specific role of the window is to facilitate pressure setting adjustments.