A plastic molding component formed by the reaction of phenol and formaldehyde. It can be heavily reinforced or "filled" with glass fibers or other materials. Phenolics are known for their high impact strength, excellent wear characteristics, and dimension ...

A small, limited-capacity central processing unit contained entirely on one semiconductor chip.

Any and all forms of water particles, liquid or solid, that fall from the atmosphere and reach the ground.

A common type of liquid-inglass thermometer, used, in meteorology, in psychrometers and as a maximum thermometer.

A wind blowing in a direction opposite to the heading of a moving object, thus opposing the object's intended progress; the opposite of a tailwind.

The quantity to be measured (or modulated, or detected, or operated upon) which is received by an instrument. Thus, for a thermometer. temperature is the input quantity.

See bimetallic thermometer.

A type of recording siphon barometer. The mechanically magnified motion of a float resting on the lower mercury surface is used to record atmospheric pressure on a rotating drum.

Pertaining to rain, or more broadly, to precipitation.

The size of the area comprising a watershed or river basin. Also called catchment area.

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 mercury barometer in which the lower mercury surface is larger in area than the upper surface. The basic construction of a cistern barometer is as follows: A glass tube one meter in length, sealed at one end is filled with mercury, and then inverted. Th ...

A type of disk hardness-gauge, especially useful in relatively soft snow. See disk hardness gauge.

A rain gauge which is placed under trees or foliage to determine the rainfall in that location. By comparing this catch with that from a rain gauge set in the open. the amount of rainfall which has been intercepted by foliage can be determined.

A tube designed to measure the rate of flow of fluids. It consists of a tube having a constriction or throat at its midsection. The difference between the pressure measured at the inlet and at the throat is a function of the fluid velocity. Compare to Pit ...

A type of cloud height indicator which uses a searchlight to project vertically a narrow beam of light onto the cloud base. The height of the cloud is determined using a clinometer, located at a known distance from the ceiling light, to measure the angle ...

The total amount of water transferred to the atmosphere by evapotranspiration.

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

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.

Difference between the temperatures of the dry-bulb and the wet-bulb thermometers of a psychrometer.