| Section A | A index | 511-519 of 917 terms |
|---|
|
aneroid barograph—(Sometimes called aneroidograph.) An aneroid barometer arranged so that the deflection of the aneroid capsule actuates a pen that graphs a record on a rotating drum. The magnification of the deflection of the capsule may be adjusted so that records of small fluctuations in pressure may be obtained. The aneroid barograph is subject to the uncertainties of the aneroid barometer and therefore must be calibrated periodically. See also barograph, microbarograph.
|
|
aneroid barometer—(Rarely called holosteric barometer, metallic barometer.) An instrument for measuring atmospheric pressure. It is constructed on the following principles: An aneroid capsule (a thin corrugated hollow disk) is partially evacuated of gas and is restrained from collapsing by an external or internal spring; the deflection of the spring will be nearly proportional to the difference between the internal and external pressures; magnification of the spring deflection is obtained both by connecting capsules in series and by mechanical linkages. The aneroid barometer is temperature compensated at a given pressure level by adjustment of the residual gas in the aneroid or by a bimetallic link arrangement. The instrument is subject to uncertainties due to variations in the elastic properties of the spring and capsules, and due to wear in the mechanical linkages. 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.
|
|
aneroid capsule—(Also called pressure capsule, sylphon, expansion chamber, bellows.) See aneroid barometer.
|
|
aneroid—1. Literally, “not wet,” containing no liquid; applied to a kind of barometer that contains no liquid, an aneroid barometer. 2. Same as aneroid barometer.
|
|
angin—A land and sea breeze system of Malaya. The land breeze is called angin-darat; the sea breeze, angin-laut.
|
|
angle of arrival—The angle between the propagation direction of an incident wave and some reference direction, which in radio engineering may be fixed relative to a receiver (e.g., the normal to a horizontal plane). Compare angle of incidence
|
|
