A type of pressure-tube anemometer, named after the inventor.

A thermopile used in some types of radiation instruments. See solarimeter.

Either of two colored luminous spots that appear at points 22

A scale with the ice point at zero degrees and the boiling point of water at 80 degrees, with pressure of one atmosphere.

Pertaining to rain, or more broadly, to precipitation.

A reversing thermometer which is encased in a strong glass outer shell that protects it against hydrostatic pressure. Compare to unprotected thermometer.

An instrument for measuring the intensity of light or the relative intensity of a pair of lights. Also called an illuminometer. If the instrument is designed to measure the intensity of light as a function of wavelength, it is called a spectrophotometer. ...

Abbreviation for mean sea level.

See captive balloon, ceiling balloon, constant-level balloon, free balloon, hurricane beacon, kytoon, Moby Dick balloon, pilot balloon, radiosonde balloon, rockoon, skyhook balloon, transosonde.

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

A forecast of weather elements of particular interest to aviation; including ceiling, visibility, upper winds, icing, turbulence, precipitation types, and storms.

An instrument consisting of a series of graduated cylinders possessing selective collection efficiencies. It is used for the measurement of quantities relating to the size distribution of cloud droplets.

A unit of distance equal to 5280 feet. It is sometimes referred to as a land mile.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

A recording variometer.

A unit of luminous intensity of a light source.

The atmospheric pressure at the level of the barometer. May or may not be the same as station pressure.

A rain gauge capable of measuring very small amounts of precipitation. Also called micropluviometer, trace recorder.

The standard deviation of a sufficiently large number of measurements of the same quantity by the same instrument or method. The non-correctable part of the inaccuracy of an instrument, it represents the limit of measurement precision. The uncertainty of ...

An instrument for determining the degree of polarization of light. See photopolarimeter.