The water volume within a specified portion of a stream channel.

Either of two colored luminous spots that appear at points 22

A class of rain gauge in which the level of the collected rain water is measured by the position of a float resting on the surface of the water.

Small particle on which water vapor condenses.

An instrument which records the duration of sunshine and gives a quantitative measure of the amount of sunshine by the action of the sun's rays upon blueprint paper. A type of sunshine recorder.

A rain gauge which indicates but does not record the amount of precipitation captured.

A weakly colored lunar halo identical in form and optical origin to the solar parhelion.

An instrument used to indicate wind direction.

A hygrometer which determines the amount of precipitable moisture in a given region of the atmosphere by measuring attenuation of radiant energy caused by the absorption bands of water vapor.

Operation mode of a communication circuit in which each end can transmit and receive, but not simultaneously.

The degree of conformity of an indicated value to an accepted standard value, or ideal value. See accuracy rating, measured accuracy.

A power supply which achieves its output regulation by means of one or more active power handling devices which are alternately placed in the "off" or "on" states. It is more efficient than linear supplies which vary the conduction of power devices to ach ...

The time required for an instrument to register a designated percentage (frequently 90%) of a step change in the variable being measured.

An instrument for measuring the pressure of the atmosphere. The two principle types are aneroid and mercurial.

A rainbow of angular radius of about 50

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.

An instrument for recording ocean waves. Most recorders are designed for recording wind waves, that is waves of periods up to about 25 seconds, but some are designed to record waves of longer periods such as tsunamis or tides.

A sudden brief increase in the speed of the wind, followed by a lull or slackening. Compare to peak gust.

A protocol similar to RS232 which makes use of differential transmission to provide high speed data transmission over significantly longer distances.

An instrument for measuring the extinction coefficient in water.