Large evaporation and small evaporation
Small evaporator is a diameter of 20 cm, about 10 cm high metal basin, pots into a knife-like, in order to prevent birds and animals drinking water, the mouth of the mouth of a set of outward out into a trumpet-like metal wire mesh.
20 o'clock every day observation, the stylus into the needle holder, read the surface height, according to the daily water level changes and precipitation calculation of evaporation.
Large-scale evaporation barrel is a mouth area of 0.3 square meters of cylindrical barrels, the bottom of the barrel has been installed in the center tube, straight tube with a stylus needle and the surface of the needle, the barrel buried in the ground, slightly higher than the ground
Measurement, the instrument on the shelf, mouth off the ground 70 cm, daily into the quantitative water, after 24 hours, with the measuring cup to measure the remaining water, the amount of water is reduced.
