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 ...

Instrument for measuring the depth of water from precipitation that is assumed to be distributed over a horizontal, impervious surface and not subject to evaporation.

See standard atmosphere.

A form of data transmission in which the bits of each character are sent one at a time along a single communication path. Compare to parallel data transmission.

Same as Aeolian.

Same as recording rain gauge.

A method of winds aloft observation essentially the same as a pilot balloon observation except the height data is derived from the radiosonde observation rather than from assumed ascension rates.

Pertaining to the action or effect of the wind. Derived from the name of the Greek god of the winds, Aeolus.

The maximum positive and negative deviation observed in testing a device under specified conditions and by a specified procedure. It is usually measured as an inaccuracy and expressed as accuracy, typically in terms of the measured variable, percent of sp ...

Difference between the instantaneous wind velocity at a point and the mean wind velocity taken over a given time interval. Also called fluctuation velocity.

An instrument used to measure the water vapor content of the air.

A wave resulting from the action of wind on a water surface.

Instrument used to measure the amount of water evaporated from the soil surface during a given time interval.

Root Mean Square. This notation is used frequently with error analysis. In that context, it is the square root of the arithmetic mean of the squares of the deviations of the individual calibration points from the theoretical or ideal response.

A thermograph in which ventilation is provided by a suction fan.

An instrument for measuring the intensity of direct solar radiation at normal incidence. See Angstrom compensation pyrheliometer, Eppley pyrheliometer, Michaelson actinograph. silver- disc pyrheliometer, spectropyrheliometer, waterflow pyrheliometer.

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.

A photometer that measures the received intensity of a distance tight source.

A wind vane used to obtain the horizontal and vertical components of the wind.

Contraction for radiosonde observation.