atmidometer

from The Century Dictionary.

• noun Atmidometers may be classed as: Micrometric, such as Lamont's, in which the gradual fall of the surface of the water in a shallow pan is measured by the turning of a micrometer-screw, or is counteracted bythe inflow of additional water pushed from a reservoir by means of a micrometer-screw.
• noun Balance atmidorneters, in which the loss of water is shown by loss of weight.
• noun The Piche evaporometer, in which the evaporating surface is a small disk of porous paper closing the lower end of a vertical tube conveying water. The amount of evaporation is shown by measuring the descent of the feed-water in the tube. See cut on page 88.
• noun The Stelling evaporometer, in which the evaporating-pan floats on the surface of a river or lake and the loss of water is measured from hour to hour by measuring either weight or volume.
• noun The lysimeter, in which the evaporation from the surface of growing plants is measured by establishing the plant in a large vessel resting on the pan of a balance.
• noun An instrument invented by Babington for measuring the evaporation from water, ice, or snow. E. H. Knight. See atmometer.

from the GNU version of the Collaborative International Dictionary of English.

• noun An instrument for measuring the evaporation from water, ice, or snow.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An instrument for measuring the evaporation from water, ice, or snow.