The statement that the viscosity of air is independent of the density of air.

Conditions to which a device is subjected, not including the variable measured by the device. See normal operating conditions, reference operating conditions.

An aneroid barometer arranged so that the deflection of the aneroid capsule actuates a pen which graphs a record on a rotating drum. Sometimes called aneroidograph.

Generally, an instrument designed to measure or estimate the blueness of the sky. See Linke-scale.

An instrument which measures the effective terrestrial radiation. See Angstrom pyrgeometer.

Any sudden and heavy rain, almost always of the shower type.

In general, pertaining to or affording an overall view. In meteorology, this term has become somewhat specialized in referring to the use of meteorological data obtained simultaneously over a wide area for the purpose of obtaining a comprehensive and near ...

A special type of radar target, usually a comer reflector, tied beneath a free balloon and designed to be an efficient reflector of radio energy.

Electromagnetic radiation lying within the wavelength interval to which the human eye is sensitive, the spectral interval from approximately 0.4 to 0.7 microns (4000 to 7000 angstroms). Bounded on the short-wavelength end by ultraviolet radiation and on t ...

A thermometer with a muslin-covered bulb which is moistened. used to measure wet-bulb temperature.

(1) The initial component or the sensing element of a measuring system. For example, the receiver of a rain gauge is the funnel which captures the rain and the receiver of a thermoelectric thermometer is the measuring thermocouple. (2) An instrument used ...

Part of a computer word that has meaning in itself, often, a byte.

Random Access Memory. The memory of a computer which can be read and written into at any location without passing through preceding locations.

The distance that an observer can see vertically into a surface-based obscuring phenomenon such as fog, rain, or snow. The distance estimate must be based upon ceiling balloon ascensions or ceiling light projector measurements.

A thermometer which utilizes the thermal properties of gas. There are two forms of this instrument: (a) a type in which the gas is kept at constant volume, and pressure is the thermometric property, and (b) a type in which the gas is kept at constant pres ...

An instrument for measuring the pressure of gases and vapors. A mercury barometer is a type of manometer.

A method of winds aloft observation accomplished by tracking a balloon-borne radar target or radiosonde with either radar or a radio theodolite.

See radar theodolite, radio direction-finder.

In thermodynamics, the integrating factor of the differential equation referred to as the first law of thermodynamics, In statistical mechanics, a measure of translational molecular kinetic energy (with three degrees of freedom). In general, the degree of ...

Generic term for rapid variations in apparent position, brightness, or color of a distant luminous. object viewed through the atmosphere.