what does altimeter mean
An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level.The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water.he greater the altitude the lower the pressure. When a barometer is supplied with a nonlinear calibration so as to indicate altitude, the instrument is called a pressure altimeter or barometric altimeter.