A rainbow of angular radius of about 50

A balloon-borne instrument for the simultaneous measurement and transmission of meteorological data. It includes transducers for the measurement of pressure, temperature, and humidity; a modulator for the conversion of the output of the transducers to a q ...

A semiconductor which exhibits rapid and extremely large changes in resistance for relatively small changes in temperature.

A transducer for converting thermal energy directly into electrical energy. It is composed of pairs of thermocouples which are connected either in series or in parallel. Thermopiles are used in thermoelectric radiation instruments when the output of a sin ...

A device used on certain types of instruments to prevent unwanted radiation from affecting the measurement of a quantity. Also called solar radiation shield.

A rain gauge which automatically records the amount of precipitation collected, as a function of time.

Same as instrument shelter.

Value of soil moisture, expressed as a percentage of the mass of dry soil, below which a plant living in the soil dies by wilting.

Same as rain-intensity gauge.

Any one of six gases, helium, neon, argon, krypton, xenon, and radon, all of whose shells of planetary electrons contain stable numbers of electrons such that the atoms are chemically inactive.

An instrument for measuring the difference of the solar radiation falling on both sides of a horizontal surface from the whole hemisphere.

A measure of the amount of "spin" (or rotation) in the atmosphere.

A device used to hold liquid-in-glass maximum and minimum thermometers in the proper recording position inside an instrument shelter, and to permit them to be read and reset. See Townsend support.

Same as photometer.

An instrument for measuring the difference between incoming and outgoing terrestrial radiation.

A recording magnetometer.

The lowest value of a measured quality at which a sensor responds. Compare to tracking.

A generic term for any machine that enables a human being to communicate with a computer.

A measurement of atmospheric conditions aloft, above the effective range of a surface weather observation. Elements evaluated include temperature, humidity, pressure, wind speed, and wind direction.

A sudden brief increase in the speed of the wind, followed by a lull or slackening. Compare to peak gust.