An instrument whose calibration is determined by comparison with an absolute instrument.

An area of low atmospheric pressure which has a closed circulation that is cyclonic (counterclockwise in northern hemisphere and clockwise in southern hemisphere).

A severe weather condition characterized by low temperatures and strong winds bearing a great amount of snow, either falling or picked up from the ground.

The cardinal points of the compass, i.e. north, south, east, west.

A protective coating applied to circuits.

Same as atmometer.

The maximum difference in output for any given input (within the specified range) when the value is approached first with increasing, and then with decreasing, input signals. Caused by energy absorption in the elements of the measuring instrument. Usually ...

General term for an instrument which records the vertical electric current in the atmosphere.

An instrument resulting from the combination of a thermograph and a hygrograph and furnishing, on the same chart, simultaneous time recording of ambient temperature and humidity.

A barometer which measures atmospheric pressure using one or a series of aneroid capsules. Also called holosteric barometer.

Thermometer used for measuring the highest temperature attained during a given interval of time, for example, a day.

An instrument, for the recording of two or more meteorological parameters, in which the ventilation is provided by a suction fan.

A temperature scale with the ice point at 273 degrees and boiling point of water at 373 degrees. It is intended to approximate the Kelvin temperature scale with sufficient accuracy for many sciences, notably meteorology.

Complementary Metal-Oxide Semiconductor. A method of making silicon chips that results in low power consumption by the circuits.

An automatic, recording cloud height indicator.

A numbering system using a base number of 2 and having only two digits: 0 and 1. The fundamental system of representing information with electrical pulses.

Clouds which cover between 6/10 and 9/10 of the sky. See Sky Terminology.

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

See calorie.

An ice coating with a consistency intermediate between glaze and rime.