The maximum deviation of any points from a straight line drawn as a "best fit" through the calibration points of an instrument with a linear response curve. Usually expressed as a percentage of full- scale range.

Read Only Memory. A memory that cannot be altered in normal use of a computer, Usually used to store information permanently, such as firmware programs.

Electromagnetic radiation lying in the wavelength interval between 0.8 micron and I millimeter. At the lower limit of this interval, the infrared radiation spectrum is bounded by visible radiation, while on its upper limit it is bounded by microwave radia ...

bucket rain gauge-A rain gauge where the precipitation collected by the receiver empties into one side of a chamber which is partioned transversely at its center and is balanced bistably upon a horizontal axis. When a predetermined amount of water has bee ...

Rain gauge which registers precipitation that is too light to be registered by ordinary recording of the depth of water from precipitation. Same as ombrometer.

An accumulation of granular ice tufts on the windward sides of exposed objects that is formed from supercooled fog or cloud and built out directly against the wind.

check chamber-A chamber use to check the sensing elements of radiosonde equipment.

Same as aneroid barometer. Holostelic means wholly made of solids, while aneroid means devoid of liquid.

Root Mean Square. This notation is used frequently with error analysis. In that context, it is the square root of the arithmetic mean of the squares of the deviations of the individual calibration points from the theoretical or ideal response.

Technically, the temperature registered by the dry-bulb thermometer of a psychrometer. However, it is identical with the temperature of the air and may also be used in that sense.

A set of regulations set down by the U.S. Civil Aeronautics Board to govern the operational control of aircraft on instrument flight. The abbreviation of this term is seldom used to denote the rules themselves, but is in popular use to describe the weathe ...

A c.g.s. (centimeter-gram-second) unit of mass. Originally defined as the mass of 1 cubic centimeter of water at 4

An early and once universal name for the mercury barometer.

A small, limited-capacity central processing unit contained entirely on one semiconductor chip.

Determined by weighing a special type of wooden stick that has been exposed in the woods, its weight being proportional to its contained water.

An instrument used for measuring the specific gravity of a liquid.

In general, solar radiation received at the earth's surface. Contracted from incoming solar radiation.

A type of atmometer. It is a pan used in the measurement of the evaporation of water into the atmosphere. The NWS Class A pan is a cylindrical container 48 inches in diameter and 10 inches deep.

An instrument for measuring the frost point of the atmosphere.

A set of weekly colored rainbow arcs sometimes discernable inside a primary rainbow.