The temperature at which the liquid and solid forms of a substance may exist in equilibrium at a given pressure (usually one standard atmosphere). The true freezing point of water is known as the ice point.

A device which automatically records the water equivalent of snow on a given surface as a function of time. A small sample of a radioactive salt is placed in the ground in a shielded collimator which directs a beam of radioactive particles upwards. A Geig ...

The most common of the principal rainbow phenomena, which appears as an arc of about 42

Same as precipitation-evaporation ratio.

meter-An instrument for measuring the transmissivity of the atmosphere; a type of transmissometer. It consists of a constant- intensity collimated light source located at a suitable distance from a photoelectric cell. Variation in the turbidity of the atm ...

See calorie.

Anemometer which generates an electrical contact output with a frequency proportional to wind speed.

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

The limiting values of ceiling, visibility, and wind, or runway visual range, established as safety minimum for aircraft landings and take-offs.

See bimetallic thermometer.

A set of electrical conductors, often on a backplane, that carry data and power signals among the various components of a computer.

The total area drained by a river and its tributaries. Same as watershed.

Wind with a speed between 4 and 6 knots (4 and 7 mph), Beaufort scale number 2.

An anemometer in which the sensor rotation is transmitted to a mechanical counter which directly integrates the air movement past the sensor. Used to determine total air passage (wind run). Average wind speed can be calculated from the difference between ...

Abbreviation for mean sea level.

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.

The transducer's output when the maximum sensed value is applied to the transducer's input. For example, the F.S. output of a 4-20 mA transmitter is 20 mA, whereas its span is only 16mA.

Wind with a speed between 41 and 47 knots (47 and 54 mph); Beaufort scale number 9.

A protocol similar to RS232 which makes use of differential transmission to provide high speed data transmission over significantly longer distances.

Apparatus using the combined simultaneous action of a bimetallic thermometer and a hair hygrometer to move a needle in front of a divided scale. fts construction permits dew point variations to be indicated approximately.