Construção e calibração de lisímetros de alta precisão

摘要: By measuring the water mass balance, weighing lysimeters are considered as standard for other methods in determination of evaporation or evapotranspiration. In order to obtain accurate measurements, must be calibrated situ, establish relationship between load cell signal and variation system. This work had objective present construction details a battery ten lysimeters, calibrate them test their performance measure variations under field conditions. Each lysimeter 1.4 x 1.9 m surface dimensions by 1.3 depth, being supported lever-load scale, whose was recorded an electronic The calibration performed using recipients known quantity, range equivalent 150 mm. results showed excellent linearity voltage all there no hysteresis. measurements evapotranspiration precision high 0.1 mm, averaging readings intervals 10 min longer, which is suitable most applications agrometeorology agricultural engineering.