An instrument for measuring snow hardness in terms of the resistance of snow to the pressure exerted by a disk attached to a spring-loaded rod, a gauge calibrated in pounds per square inch registers the amount of resistance. See Canadian hardness gauge.

A line of equal or constant temperature.

The length of fluid flow (gas or liquid) past a sensor required for the sensor to respond to 63.2% of a step change in speed. Expressed in feet or meters. For anemometers, this value is calculated from time constant times wind tunnel speed.

Instrument for measuring the mean intensity of glo global solar radiation (direct and diffuse) near the earth's surface in a specified time interval.

An atmospheric phenomenon, other than clouds, which obscures a portion of the sky from the point of observation. Also called obscuration.

The probability distribution of random errors, typically a normal distribution with a zero mean.

See gain.

Ragged low clouds, usually stratus fractus. Most often applied when such clouds are moving rapidly beneath a layer of nimbostratus.

Rate of wind movement in distance per unit time.

The algebraic difference between the upper and lower limits of the measuring range of an instrument, i.e. a thermometer with a range of -35 to 50

An area of low barometric pressure, with its attendant system of winds. Also called a depression or cyclone.

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 ...

Transistor-Transistor Logic.

The maximum rate at which precipitation can pass through the surface into the soil, for a given soil in a given condition.

The source of illumination for an antenna reflector. Also called antenna feed.

Same as precipitation- effectiveness index.

Abbreviation for radio frequency.

The portion of the precipitation on the land which ultimately reaches the streams. especially the water from rain or melted snow that flows over the surface.

A graphical representation of a frequency distribution. The range of the variable is divided into class intervals for which the frequency of occurrence is represented by a rectangular column. The height of the column is proportional to the frequency of ob ...

Precipitation composed of white or translucent ice crystals, chiefly in complex branched hexagonal forms.