A type of disk hardness-gauge, especially useful in relatively soft snow. See disk hardness gauge.

A unit of energy equal to 101 ergs or to 0.2389 calories.

A type of cooling-power anemometer based upon the principle that the time constant of a thermometer is a function of its ventilation.

The volume of water required to cover one acre to a depth of one foot: 43,560 cubic feet.

An instrument for measuring the extinction coefficient in water.

The state of the atmosphere, mainly with respect to its effects upon life and human activities. As distinguished from climate, weather consists of the short-term (minutes to months) variations of the atmosphere.

To free something from the binding action of ice by warming it to a temperature above the melting point of ice. Also, a warm spell when ice and snow melt.

A wind blowing in the same direction as the heading of a moving object. thus assisting the object's intended progress. The opposite of a head wind.

The frequency of a carrier wave.

Thermometer for measuring the temperature in the soil at different depths.

That temperature at which, in a specified latitude, the reading of a particular barometer requires no temperature or latitude correction.

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.

A conductor or system of conductors for radiating and/or receiving radio energy. Also called aerial.

A temperature-sensing element which converts thermal energy directly into electrical energy. In its basic form it consists of two dissimilar metallic conductors connected in a closed loop. Each junction forms a thermocouple. If one thermocouple is maintai ...

Same as ombrometer.

Operation mode of a communication circuit in which each end can simultaneously transmit and receive.

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 ...

The correctable part of the inaccuracy of an instrument.

A special form of the aspiration psychrometer. developed by Assmann, in which the thermometric elements are well shielded from radiation. Psychrometric measurements may be taken with the instrument in the presence of direct solar radiation.

A pyranometer developed by M. Robitzsch. Its design utilizes three bimetallic strips which are exposed horizontally at the center of a hemispherical glass bowl. The outer strips are white reflectors and the center strip is a blackened absorber. The bimeta ...