An Instrument used to determine dew point.

Same as dew-point hygrometer.

An instrument used for measuring the specific gravity of a liquid.

Determined by weighing a special type of wooden stick that has been exposed in the woods, its weight being proportional to its contained water.

See calorie.

An instrument for measuring radiant energy. It consists of an ether differential thermometer with blackened bulbs. One of the bulbs is exposed to the unknown radiation and the other to a black body source whose temperature can be varied. Equality of radia ...

The volume of liquid water evaporated per unit area in unit time. usually measured as the depth of liquid water lost per unit time from the whole area.

An anemometer which measures wind speed in terms of the drag which the wind exerts on a solid body. See bridled-cup anemometer, normal-plate anemometer, pendulum anemometer.

A standard interface between a computer input/output port and a peripheral device. Signal properties including time duration, voltage. and current, are specified by the Electronic Industries Association.

A protocol similar to RS232 which makes use of differential transmission to provide high speed data transmission over significantly longer distances.

check chamber-A chamber use to check the sensing elements of radiosonde equipment.

An instrument used to measure changes in the level of the water in an evaporation pan. The gauge is normally placed in a Stillwell and adjusted so that the point of the hook just breaks the water surface. The change in water level is read on the attached ...

A vent used with pressure sensors to reduce the effect of wind on the pressure inlet. It is normally mounted remotely and connected to the sensor using airtight tubing.

bucket rain gauge-A rain gauge where the precipitation collected by the receiver empties into one side of a chamber which is partioned transversely at its center and is balanced bistably upon a horizontal axis. When a predetermined amount of water has bee ...

The combined processes by which water is transferred from the earth's surface to the atmosphere: evaporation of liquid or solid water plus transpiration from plants.

An early and once universal name for the mercury barometer.

The water portion of the earth as distinguished from the solid part, called the lithosphere, and from the gaseous outer envelope, called the atmosphere.

In a system of moist air, the dimensionless ratio of the mass of water vapor to the mass of dry air. For many purposes, the mixing ratio may be approximated by the specific humidity.

A hypothetical body which absorbs some constant fraction, between zero and one, of all electromagnetic radiation incident upon it, which fraction is the absorptivity and is independent of wavelength. Compare to black body, white body.

Liquid water at temperatures colder than freezing.