Any one of numerous devices for the measurement of either speed alone or of both direction and speed (set and drift) in flowing water.

Temperature assumed by an unsaturated air parcel when brought adiabatically to a standard pressure (1,000 mb).

A balloon designed to float at a constant pressure level. This may be accomplished by a pressure valve which controls the release of ballast so as to maintain flight above a selected pressure level until the supply of ballast is exhausted. See Moby Dick b ...

Of or pertaining to rain.

A barometer which measures atmospheric pressure using one or a series of aneroid capsules. Also called holosteric barometer.

The study of waters (including oceans, lakes, and rivers) embracing either: (a) their physical characteristics, from the standpoint of the oceanographer or limnologist; or (b) the elements affecting safe navigation, from the point of view of the mariner. ...

A self-recording thermometer.

The part of a measuring instrument which responds directly to changes in the environment.

A type of electrical thermometer consisting of two thermocouples which are series-connected with a potentiometer and a constant-temperature bath. One couple, called the reference junction, is placed in a constant-temperature bath, while the other is used ...

The temperature to which a sample of air must be cooled, while the mixing ratio and barometric pressure remain constant, in order to attain saturation by water vapor. When this temperature is below O

The change in barometric pressure within a specified period of time (typically 3 hours for meteorological observations).

Pertaining to measurements or devices in which the output vanes in discrete steps, i.e. on-off or pulse signals. Compare to analog.

Anemometer which measures wind speed by the speed of rotation of 3 or 4 hemispherical or conical cups, each fixed to the end of a horizontal arm projecting from a vertical axis. See condenser-discharge anemometer, contact anemometer. Compare to bridled-cu ...

See gust and peak gust.

Same as aneroid barometer. Holostelic means wholly made of solids, while aneroid means devoid of liquid.

A device for measuring the river stage. Also called stream gauge.

Same as luminous intensity.

The total of all deviations of a transducer's output from a specified straight line in a constant environment.

A wooden enclosure about sixteen feet square and eight feet high with a precipitation gauge at its center. The function of the fence is to minimize eddies around the gauge and thus insure a catch that is representative of the actual rainfall or snowfall.

A small, limited-capacity central processing unit contained entirely on one semiconductor chip.