Talk:Atmometer

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Atmometers are used to calculate the daily evaporation rate from irrigated field crops and to schedule irrigation. The calculated evaporation rate from the atmometer reading is combined with the transpiration of the crop plants to determine water useage (evapotranspiration)and adjusted for any rainfall that was received and in order to determine the amount of irrigation required on a daily basis. This is a valuable aid to assist in providing optimum moisture (water balance) in the soil and optimum growing conditions for various crops.

[edit] from Wikipedia (German)

part translated using Babelfish of http://de.wikipedia.org/wiki/Atmometer

A Atmometer (Greek, also Atmidometer or Evaporometer), is an evaporation measurer, an instrument for measuring the size of the evaporation.

Different procedures are to be measured possible around the evaporation. A simple possibility the evaporation to measure, consists exposing of it containers with a certain to quantity water of the effect of atmospheric air. The difference between the quantity of the originally existing water and that at the expiration of a certain time stayed, can the size of the evaporation be determined. The difference can be determined either over the mass (over the weight) or the volume; from both one, if the opening of the container admits is, can compute the quantity of the water evaporated.

This procedure seems so simple, offers it nevertheless, if larger accuracy is demanded, some problems.

The Atmometer can be divided two classes, dependent on it whether the evaporation by the decrease of the volume or by the decrease in weight the evaporation of suspended water is determined. The Atmometer of the first class has the disadvantage that they are also often destroyed during frost weather for observation unsuitable and by the frost. The most well-known apparatuses of this kind are designed by Muehry, Prestel, Lament, Piche and morning star. To this group belongs also Dufours Siccimeter, which is to indicate the difference between rain quantity and evaporation. Many constructions use the evaporation, which is determined by means of weighing. The most well-known are indicated of Saussure and game, by which the latter is represented in the design.

The Atmometer of game essentially consists of a flat-like container C, which on one device A similar can be put on to the briefwaage. If the dished plate is water empty, then the pointer D stands on the nullstrich of the scale; if it is loaded however by cast in water, then the pointer on the scale is lifted. During the observation the bowl C filled with water, on which pin notes B of the balance set and the conditions of the pointer D at the graduated quadrant G, on that from the balance is removed and, set according to process of the observation period (24 hours) again on the balance and, determined the new situation of the pointer. The difference of the two reading off indicates the weight of the water evaporated or its height depending upon the nature of the division either in millimeters. The whole balancing device is enclosed in a small box E holding in whose unterm subject a dished plate with chlorine calcium F is set up, in order air in the inside the same drying and protecting the metal parts of the instrument against oxidation.

When result that results so far employee evaporation observations that the same show conditions of the evaporation because of the influence, which the temperature and the air movement exert only in insufficient way, as them take place in nature. In addition only larger evaporation containers are or if necessary evaporation measurers suitable, with whom the actual evaporation container is let in into a larger, with water filled.

part translated using SYSTRAN...

The Atmometer can be divided two classes, dependently of it whether the evaporation by the decrease of the volume or by the decrease in weight the evaporation of suspended water is determined. The Atmometer of the first class has the disadvantage that they are also often destroyed during frost weather to the observation unsuitable and by the frost. The most well-known apparatuses of this kind are designed of Mühry, Prestel, Lament, Piche and morning star. To this group belongs also Dufour Siccimeter, which is to indicate the difference between rain quantity and evaporation. Many constructions use the evaporation, which is determined by means of weighing. The most well-known are indicated of Saussure and game, by which the latter is represented in the design.

The Atmometer essentially exists of game from a flat-like container C, which on one device A similar can be put on to the Briefwaage. If the dished plate is water empty, then the pointer D stands on the Nullstrich of the scale; if it is loaded however by cast in water, then the pointer is lifted on the scale. During the observation the bowl C is filled with water, on which pin notes B of the balance set and the conditions of the pointer D at the graduated quadrant G, on that of the balance

When result that results so far employee evaporation observations that the same show conditions of the evaporation because of the influence, which the temperature and the air movement exert only in insufficient way, as them take place in nature. In addition only larger evaporation containers are or if necessary evaporation measurers suitable, with whom the actual evaporation container is let in into a larger, with water filled. —Preceding unsigned comment added by 80.42.216.34 (talk) 17:06, 24 April 2008 (UTC)