See gain.

See hurricane beacon.

A unit of pressure used principally in oceanography. One decibar (10' dynes/cm2) equals 0.1 bar. In the ocean, hydrostatic pressure in decibars very nearly equals the corresponding depth in meters.

A device for measuring the height of tide. It may be simply a graduated staff in a sheltered location where visual observations can be made, or it may consist of an elaborate recording instrument (sometimes called a marigraph) making a continuous graphic ...

The number of cycles per second between the limits of a frequency band.

A graphical representation of a frequency distribution. The range of the variable is divided into class intervals for which the frequency of occurrence is represented by a rectangular column. The height of the column is proportional to the frequency of ob ...

A pressure tube anemometer, consisting of a pitot tube mounted on the windward end of a wind vane and a suitable manometer to measure the developed pressure and calibrated in units of wind.

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.

A liquid-in-metal thermometer in which mercury is enclosed in a steel envelope. The change in internal pressure caused by the temperature variation is measured by a Bourdon tube which is connected to the mercury by a capillary tube. This instrument is hig ...

A line of equal or constant pressure.

Same as ombrometer.

A cone-tipped metal rod designed to be driven downward into deposited snow or firn. The measured amount of force required to drive the rod a given distance is an indication of the physical properties of the snow or firn.

The range through which the input may be varied without initiating a response. Usually expressed as a percentage of full-scale range.

A component of a radiosonde consisting of a series of alternate electrically conducting and insulating strips. As these are scanned by a contact the radiosonde transmits temperature and humidity signals alternately. The contact may be a baroswitch as in t ...

A very sensitive electrostatic electrometer for measuring small potential differences.

A fixed support for mounting maximum and minimum thermometers of the liquid-in-glass type. The support holds the thermometers at the correct operating attitude and also permits their rotation for resetting when desired.

A self-recording thermometer.

Line drawn through geographical points recording equal amounts of precipitation during a given time period or for a particular storm.

Same as wave pole.

Same as fogbow.