See Koschmieder's law.

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 ...

The flux of visible radiation, so weighted as to account for the manner in which the response of the human eye varies with the Wavelength of radiation. The basic unit for luminous flux is the lumen,

An instrument used to determine atmospheric pressure or elevation by observing the boiling point of water or both liquids. The sensitivity of the hypsometer increases with decreasing pressure, making it more useful for high altitude work.

Conditions to which a device is subjected, not including the variable measured by the device. See normal operating conditions, reference operating conditions.

The effect upon the measurement of rainfall caused by the presence of the rain gauge.

See hurricane beacon.

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 ...

Overflowing by water of the normal confines of a stream or other body of water, or accumulation of water by drainage over areas which are not normally submerged.

The amount of moisture which, if available, would be removed from a given land area by evapotranspiration. Expressed in units of water depth.

The process by which water in plants is transferred as water vapor to the atmosphere. Also, the amount of water so transferred.

A hygrometer which uses a transducing element whose electrical properties are a function of atmospheric water vapor content. The humidity strip and carbon-film hygrometer element are examples of such a transducer.

A class of rain gauge in which the level of the collected rain water is measured by the position of a float resting on the surface of the water.

The transducer of any hygrometer, i.e. that part of a hygrometer that quantitatively "senses" atmospheric water vapor.

A fixed-length group of bits representing the large data element handled as a unit by a computer. Word length is determined by the capacity of the CPU registers.

A device for measuring the frequency of occurrence of atmospherics whose intensity is greater than a predetermined level.

A coating of ice, generally clear and smooth. formed by the freezing of supercooled water on a surface.

The temperature at which an object gives out as much radiation as it receives from its surroundings.

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

The group of bits which a computer processes as a unit; often, 8 bits.