An instrument which measures the instantaneous rate at which rain is falling on a given surface. Also called a rate-of-rainfall gauge.

The ratio of the actual amount of water evaporated into the atmosphere to the evaporative power. Also called relative evaporation.

An instrument used to measure the amount of dew formed on a given surface.

Instrument which measures and records the amount of evaporation over time.

An instrument used to measure the water vapor content of the air.

Similar to the spectroheliograph, but used for visual instead of photographic purposes.

A protocol similar to RS232 which permits data interchange on multidrop networks of up to 32 nodes using a single twisted pair cable. In order for this protocol to be used, each device on a network must have some level of intelligence in order establish o ...

Water vapor content of the air. See absolute humidity, dew point, mixing ratio, relative humidity, specific humidity.

A type of pressure-tube anemometer, named after the inventor.

Transistor-Transistor Logic.

An aneroid barograph designed to record atmospheric pressure variations of very small magnitude.

The flux of visible radiation, so weighted as to account for the manner in which the response of the human eye varies with the Wavelength of radiation. The basic unit for luminous flux is the lumen,

The audio-frequency signal transmitted by the Diamond-Hinman radiosonde when the baroswitch pen passes each fifth contact of the commutator up to a number determined by the design of the commutator. It then signals every contact except the fifth, which is ...

In a system of moist air, the dimensionless ratio of the mass of water vapor to the total mass of the system.

Technically, the temperature registered by the dry-bulb thermometer of a psychrometer. However, it is identical with the temperature of the air and may also be used in that sense.

An instrument which measures the transmissivity of the atmosphere between two points for the determination of visual range.

For a given locality and month, an empirical expression devised for the purpose of classifying climates numerically on the basis of precipitation and evaporation.

The temperature at which all three phases of a substance can exist in equilibrium. This temperature occurs at only one pressure. The triple-point of water is 273.16 K and is the basis of the Kelvin scale.

A system of physical units based upon the use of the meter, the metric ton (106 grams), and the second as elementary quantities of length, mass, and time, respectively.

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