pattern barometer-Mercurial barometer with a fixed scale and cistern and which therefore requires only one adjustment before each reading.

The point (physical and/or electrical) where two distinct data processing elements meet.

Clouds which cover between 6/10 and 9/10 of the sky. See Sky Terminology.

Precipitation from a cumuliform cloud. Characterized by the suddenness of beginning and ending, by the rapid change in intensity, and usually by a rapid change in the condition of the sky. The solid or liquid water particles are usually bigger than the co ...

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.

The water portion of the earth as distinguished from the solid part, called the lithosphere, and from the gaseous outer envelope, called the atmosphere.

General name for an instrument which measures the evaporation rate of water into the atmosphere. See clay atmometer, evaporation pan, evapotranspirometer, Livingston sphere, Piche evaporimeter, radio atmometer.

The play or loose motion in an instrument due to the clearance existing between mechanically contacting parts.

Difference between the temperatures of the dry-bulb and the wet-bulb thermometers of a psychrometer.

Downward scattered and reflected solar radiation, coming from the whole hemisphere with the exception of the solid angle of the sun's disc on a surface perpendicular to the axis of this cone.

A term used to describe a sensor (or sensors), the associated transducer(s), and the data readout or recording device.

Wind with a speed between 11 and 16 knots (13 and 18 mph); Beaufort scale number 4.

Same as ombrometer.

An aneroid barograph designed to record atmospheric pressure variations of very small magnitude.

Any device or instrument for measuring salinity, especially one based on electrical conductivity methods.

The element directly responsive to the value of the measured variable.

A small anemometer with flat vanes which indicates the number of linear feet or meters of air which have passed the instrument during its exposure.

A special type of radar target, usually a comer reflector, tied beneath a free balloon and designed to be an efficient reflector of radio energy.

Board that holds graph paper on which is plotted information obtained from a pilot-balloon observation.

Hygrometer in which the dew (frost) point is determined by observing the temperature of an artificially cooled surface at the moment at which dew (frost) first appears on it.