Barometer Definitions for Land Surveyors

barometer–An instrument for measuring atmospheric pressure. There are two general types of barometers: those in which atmospheric pressure is balanced by the weight of a column of liquid (usually mercury); and those in which atmospheric pressure is balanced by some elastic device; aneroid barometers (barometers without liquid). A third kind of device for measuring atmospheric pressure is the hypsometer, which is not classed as a barometer. See also altimeter.

barometric altimeter—See altimeter; barometer

barometric elevation—Elevation determined with a barometer.

barometric gradient—The rate of fall in atmospheric pressure between two stations; the slope of an isobaric surface.

barometric hypsometry—See hypsometry.

barometric leveling—See leveling, barometric.

barometric pressure—A measure of atmospheric pressure. Variations in pressure can adversely affect distance measurements. Some EDMs allow the input of atmospheric pressure values to compute corrected distances. See also error, natural.

barometric surface—A surface having the same barometric pressure at all points; an isobaric surface.

barometric tendency—The change of atmospheric pressure during the last two (generally three) hours before a regular observation.

barometric tide—A regular daily fluctuation in barometric pressure.

barometric wave—A change of atmospheric pressure that occurs progressively over an area.

barometry—The science or process of making barometric measurements.

Source: NSPS “Definitions of Surveying and Related Terms“, used with permission.

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