What is the primary function of the altimeter in the pitot-static system?

The primary function of the altimeter within the pitot-static system is to indicate altitude. The altimeter utilizes atmospheric pressure readings from the static port to determine the altitude of the aircraft above sea level. As an aircraft climbs or descends, the ambient air pressure changes; the altimeter measures these changes and translates them into corresponding altitude readings.

Understanding the role of the altimeter within the broader context of flight instrumentation is important. While the pitot tube, another component of the pitot-static system, directly measures dynamic pressure to determine airspeed, the altimeter specifically interprets static pressure to provide altitude information. Therefore, the altimeter is critical for ensuring safe vertical separation between aircraft and for adherence to altitude assignments by air traffic control.