The true freezing point of water. The temperature at which a mixture of air-saturated pure water and pure ice may exist in equilibrium at a pressure of one standard atmosphere.

A liquid-in-metal thermometer in which mercury is enclosed in a steel envelope. The change in internal pressure caused by the temperature variation is measured by a Bourdon tube which is connected to the mercury by a capillary tube. This instrument is hig ...

American Standard Code for Information Interchange. A standard code used to represent data using 8 bits (7 data bits and I parity bit) per character.

An instrument for photographing the corona and prominences of the sun at times other than at solar eclipse.

A device attached to a meteorological instrument to provide ventilation; usually a suction fan.

A recording anemometer.

In folklore, a name for rain.

A clockwise change in wind direction. Veering winds with height are indicative of warm air advection (WAA).

Same as ceiling light.

The process by which events in the real world are translated into machine-readable signals.

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

A class of instruments employed to determine the electric potential at a point in the atmosphere, and ultimately the atmospheric electric field.

An instrument for the measurement of both solar and terrestrial radiation.

In the direction from which the wind is blowing.

An instrument for recording ocean waves. Most recorders are designed for recording wind waves, that is waves of periods up to about 25 seconds, but some are designed to record waves of longer periods such as tsunamis or tides.

Central Processing Unit. The part of a computer which controls and directs all functions.

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

The record obtained from a bolometer.

An instrument which indicates the presence of precipitation. The ombroscope consists of a heated, water-sensitive surface which indicates by mechanical or electrical techniques the occurrence of precipitation.

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.