What does the cockpit differential pressure display measure?

The cockpit differential pressure display measures the difference between air pressures inside and outside the cockpit. This measurement is crucial for the aircraft's pressurization system, as it helps ensure that the cabin maintains a safe and comfortable environment for passengers and crew at high altitudes where external air pressure is significantly lower than that in the cabin. Maintaining a proper pressure differential is vital for safety, as it prevents structural damage to the aircraft and ensures that the cabin altitude remains at a level that supports human physiology.

While atmospheric pressure is related to this concept, the differential pressure display specifically focuses on the difference, making it distinct from simply measuring atmospheric pressure alone. Fuel pressure and cabin temperature do not pertain to the pressure difference relevant to cockpit safety and comfort in the same manner, thus they are not applicable to this question.