What controls the operation of the cabin pressure regulator?

The operation of the cabin pressure regulator is primarily controlled by cabin altitude. As an aircraft ascends or descends, the cabin altitude changes, which is crucial for maintaining a safe and comfortable environment for passengers and crew. The regulator reacts to variations in cabin altitude to ensure that the pressure inside the cabin is adequately adjusted, maintaining a level that prevents hypoxia and ensures passenger comfort.

While the other factors, such as altitude settings, temperature regulations, and air density, may influence cabin pressure indirectly, they do not serve as the primary control mechanism for the cabin pressure regulator. Thus, cabin altitude is the definitive element governing how the regulator operates in response to the aircraft's altitude changes.