Thermometer used for measuring the highest temperature attained during a given interval of time, for example, a day.

The height at which the maximum wind speed occurs, determined in a winds-aloft observation.

The statement that the viscosity of air is independent of the density of air.

The temperature at which an object gives out as much radiation as it receives from its surroundings.

The average temperature of the air as indicated by a properly exposed thermometer for a given time period, usually a day, a month, or a year.

The maximum positive and negative deviation observed in testing a device under specified conditions and by a specified procedure. It is usually measured as an inaccuracy and expressed as accuracy, typically in terms of the measured variable, percent of sp ...

The level at which ice crystals and snowflakes melt as they descend through the atmosphere.

The temperature at which a solid substance undergoes fusion, i.e. melts, changes from solid to liquid form. All substances have their characteristic melting points. For very pure substances the temperature range over which the process of fusion occurs is ...

The upper surface of a column of liquid.

Same as mercury barometer.

A metallic element of atomic weight 200.6 1, unique (for metals) in that it remains liquid under all but very extreme temperatures.

Barometer in which pressure is determined by balancing air pressure against the weight of a column of mercury in an evacuated glass tube.

A liquid-in-glass or liquid-in-metal thermometer using mercury as the liquid.

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

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 record obtained from a meteorograph. A chart in which meteorological variables are plotted against time.

An instrument which automatically records the measurement of two or more meteorological elements.

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.

A pyrheliometer of the bimetallic type used to measure the intensity of direct solar radiation.

That portion of the record of a microbarograph between any two (or a specified small number) of successive crossings of the average pressure level (in the same direction). Analogous to microseism.