A radiosonde whose carrier wave is modulated by audio-frequency signals whose frequency is controlled by the sensing elements of the instrument.

A relatively small-scale, upward moving current of air.

Small particle on which water vapor condenses.

A mercury barometer designed for use aboard ship. The instrument is of the fixed-cistern type (see Kew barometer). The mercury tube is constructed with a wide bore for its upper portion and with a capillary bore for its lower portion. This is done to incr ...

The general term for anemometers operating on the principle that the heat transfer to air from an object at an elevated temperature is a function of the air speed. Examples are the hot-wire anemometer and the katathermometer.

A type of disk hardness-gauge, especially useful in relatively soft snow. See disk hardness gauge.

A defective maximum thermometer of the liquid-inglass type in which the mercury flows too freely through the constriction. Such a thermometer will indicate a maximum temperature that is too low.

An element that can control current without moving parts, heated filaments, or vacuum gaps.

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

A modification of the dew cell used in radiosonde equipment.

A type of instrument shelter. It is a wooden box painted white with double louvered sides and mounted on a stand four feet above the ground.

The scientific study of the waters of the earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of water in streams, lakes, and on or below the land surface. In terms of the hydrologic cycle, the ...

A class of rain gauge in which the level of the collected rain water is measured by the position of a float resting on the surface of the water.

Particle on which the freezing of water occurs.

An instrument for measuring the ultraviolet in solar and sky radiation.

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

A definite portion of a stream channel, commonly taken between two gauging stations, but may be taken between any two specified points.

The audio-frequency signal transmitted by the Diamond-Hinman radiosonde when the baroswitch pen passes each fifteenth contact of the commutator, up to a number determined by the design of the commutator, and each fifth contact thereafter. This signal is t ...

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

Same as mirror nephoscope.