A form of psychrometer with wet-bulb and dry-bulb thermometers mounted on opposite sides of a specialty designed graph of the psychrometric tables. It is so arranged that the intersections of two curves determined by the wet-bulb and dry-bulb readings -yi ...

An instrument used for the measurement of the reflecting, power (the albedo) of a surface. A pyranometer adapted for the measurement of radiation reflected from the earth's surface is sometimes employed as an albedometer.

A device which automatically records the water equivalent of snow on a given surface as a function of time. A small sample of a radioactive salt is placed in the ground in a shielded collimator which directs a beam of radioactive particles upwards. A Geig ...

See stage.

A instrument designed to study small fluctuations of some quantity. The microbarograph is an example of a recording pressure variometer.

Generally, the relative states of inflow, outflow, and storage of moisture over a given area of earth's surface.

A clay atmometer consisting of a hollow ceramic sphere through which evaporation occurs. Evaporation is measured by the loss of water from the reservoir which feeds the sphere.

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 ...

An instrument for collecting liquid water from the atmosphere.

A measure of luminous flux remaining in a light beam after it has passed through a specified distance of the atmosphere.

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

A wave disturbance in airflow due to some barrier in the flow. i.e. a hill or mountain.

The line-of-sight distance between two objects.

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

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.

An evaporation pan in which the evaporation is measured from water in a pan floating in a larger body of water.

A precipitation amount of less than 0.005 inches. Also, the record made by any self-registering instrument.

The change in barometric pressure within a specified period of time (typically 3 hours for meteorological observations).

Anemometer whicb measures wind speed by measuring the degree of cooling of a metal wire heated by an electric current. A type of cooling power anemometer.

Instrument for measuring the intensity of radiant energy. Its principle is based on the variation of electrical resistance, with the incoming radiation, of one or both the metallic strips which the instrument comprises.