An instrument which measures evaporation by measuring the loss of water from a burette reservoir through a ceramic disc.

An instrument used to measure the water vapor content of the air. A type of hygrometer. It consists of a wet-bulb and a dry-bulb thermometer. See aspiration psychrometer, Assmann psychrometer. hygrodeik, sling psychrometer.

Any quantity, such as force velocity, or acceleration, which has both magnitude and direction at each point in space, as opposed to scalar which has magnitude only. Such a quantity may be represented geometrically by an arrow of length proportional to its ...

A type of directional antenna used on some types of radar and radio equipment consisting of an array of elemental, single- wire dipole antennas and reflectors.

Apparatus designed to measure and record the size distribution of raindrops as they occur in the atmosphere.

A unit of mass numerically equal to the molecular weight of the substance. The gram-mote or gram-molecule is the mass in grams numerically equal to the molecular weight, i.e. a gram-mole of oxygen is 32 grams.

Occupational Safety and Health Administration. A regulatory office of the U.S. Department of Labor.

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.

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

A type of instrument shelter. It is a wooden box painted white with double louvered sides and mounted on a stand four feet above the ground.

The record or trace made by a microbarograph.

The audio-frequency signal transmitted by the Diamond-Hinman radiosonde when the baroswitch pen passes each fifteenth contact of the commutator, up to a number determined by the design of the commutator, and each fifth contact thereafter. This signal is t ...

The inaccuracy that the manufacturer permits when the unit is calibrated in the factory.

In a system of moist air, the dimensionless ratio of the mass of water vapor to the mass of dry air. For many purposes, the mixing ratio may be approximated by the specific humidity.

A sunshine recorder of the type in which the time scale is supplied by a chronograph. It consists of two bulbs, one of which is blackened, which communicate through a glass tube of small diameter. The tube is partially filled with mercury and contains two ...

An instrument for taking photographs of an image of the sun in monochromatic light.

A chronograph used to make a time-record of certain measured meteorological elements. The most common type, the triple register, records wind direction and speed, duration of sunshine, and amount of rainfall (sensed respectively by a contact anemometer, M ...

A recording hair hygrometer.

The ratios, to the mean wind speed, of the average magnitudes of the component fluctuations of the wind along three mutually perpendicular axes.

The atmospheric pressure at the level of the barometer. May or may not be the same as station pressure.