Same as aneroid barometer. Holostelic means wholly made of solids, while aneroid means devoid of liquid.

Erasable Programmable Read Only Memory. Programable read-only memory which can be erased, usually by ultraviolet light, and re-programmed.

Same as wind sock.

Any conventional barometer fitted with an extended scale so that atmospheric pressure measurements may be made at both high and low altitudes.

See instrument error, observational error. random error, standard error, systematic error.

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

Automated Local Evaluation in Real Time. Network of automatic rain gauges that transmit via VHF radio link when precipitation occurs. Some sites are also equipped with other sensors such as temperature, wind, pressure, river stage or tide level. More info ...

A basic equation in daytime visual range theory, relating the apparent luminance of a distant black object, the apparent luminance of the background sky above the horizon, and the extinction coefficient of the atmosphere, or the air layer near the ground. ...

A unit of illuminance or illumination equal to one lumen per foot'. This is the illuminance provided by a light source of one candle at a distance of one foot.

The distance or length of flow of the air past a point during a given interval of time.

A momentary decrease in the speed of the wind.

The energy of any type of electromagnetic radiation. Also called radiation.

The unit of speed in the nautical system; one nautical mile per hour. It is equal to 1.1508 statute miles per hour or 0.5144 meters per second.

The part of a measuring instrument which responds directly to changes in the environment.

The officially designated elevation of an airport above mean sea level, taken as the highest point on any of the runways of the airport. Same as airport elevation.

The length of fluid flow (gas or liquid) past a sensor required for the sensor to respond to 63.2% of a step change in speed. Expressed in feet or meters. For anemometers, this value is calculated from time constant times wind tunnel speed.

The most common of the principal rainbow phenomena, which appears as an arc of about 42

An instrument used for measuring the specific gravity of a liquid.

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.

A balloon used to carry a radiosonde aloft, considerably larger than pilot balloons or ceiling balloons.