Meteorological Instruments

the instruments and equipment used to measure and record the values of meteorological elements. The instruments are designed to function under natural conditions in any climatic zone. Consequently they must operate reliably, give stable readings over a wide temperature range and under conditions of high humidity and high precipitation, and be unaffected by high wind and dust. To make the results of the measurements taken at the various weather stations comparable, the instruments are of the same types and are set up in such a way that their readings are independent of incidental local conditions.

In order to measure (record) air and soil temperatures, various types of meteorological thermometers and thermographs are used. The humidity of the air is measured with psychrometers, hygrometers, and hygrographs; atmospheric pressure is measured with barometers, aneroid barometers, barographs, and hypsometers. Wind speed and direction are measured with anemometers, anemographs, anemorumbometers, anemorumbographs, and wind vanes. The amount and intensity of precipitation are determined by means of rain gauges, precipitation gauges, and pluviographs. The intensity of solar radiation and the radiation from the earth’s surface and the atmosphere are measured with pyrheliometers, pyrgeometers, actinometers, pyranometers, pyranographs, albedometers, and radiation balance meters; sunshine duration is recorded by heliographs. The reserves of water in snow cover are measured with a snow sampler, and dew is measured with a drosometer; evaporation with an atmometer, and visibility with a nephelometer and a visibility meter. The parameters of atmospheric electricity are measured with electrometers. Remote and automatic meteorological instruments for the measurement of one or several meteorological elements are becoming increasingly important.