PRESSURE ALTIMETER An aneroid barometer calibrated to indicate altitude in feet instead of units of pressure. It is read accurately only in a standard atmosphere and when the correct altimeter setting is used.
Standard AtmosphereA hypothetical vertical distribution of atmospheric temperature, pressure, and density that, by international agreement, is taken to be representative of the atmosphere for purposes of pressure altimeter calibrations, ...
There are two general types of altimeters: (a) the pressure altimeter, which gives an approximate measure of altitude from a pressure measurement and an assumed standard temperature distribution; and (b) the radio altimeter, ...
Pressure AltimeterAn aneroid barometer calibrated to indicate altitude in feet instead of units of pressure. It is read accurately only in a standard atmosphere and when the correct altimeter setting is used.
It is used as a basis for determining elevations, as the reference for all altitudes in upper air measurements, and as the level above which altitude is measured by a pressure altimeter for aviation. Often referred to as MSL. See sea level.
An instrument that indicates the altitude of an object above a fixed level. Pressure altimeters use an aneroid barometer with a scale graduated in altitude instead of pressure.
Altimeter Setting ...
An instrument that indicates the altitude (1) of an object with respect to a reference level such as sea level; examples include pressure altimeters and radio altimeters .
anemometer ...
over a 19-year period, usually determined from the hourly heights observed above a fixed reference level. (2) In aerology, the reference surface for all altitudes. (3) In aviation, the level above which altitude is measured by a pressure altimeter.
See barometer, aneroid barograph, pressure altimeter, altimeter-setting indicator.
U.S. Weather Bureau, 1941: Barometers and the Measurement of Atmospheric Pressure, Circular F, 7th ed., rev., 21-25.
Pressure altimeters use an aneroid barometer with a scale graduated in altitude instead of pressure.Altimeter SettingA correction of the station pressure to sea level used by aviation.
 See also: Pressure, Temperature, Atmospheric pressure, Wind, Air
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