Altimeter Instrument that measures the altitude of the land surface or of any object, such as an airplane. The mechanical pressure altimeter measures atmospheric pressure relative to sea level through a series of bellows, gears, and springs, which move pointers on... more
Altimeter An altimeter is an instrument that measures altitude (the distance above sea level or some other chosen point). Aircraft use two different types: the aneroid (barometric) altimeter and the radio altimeter. The aneroid altimeter derives a quantity for alt... more