[Design and performance of a hydraulic lysimeter for measurement of potencial evapotranspiration] | Diseno y funcionamiento de un lisimetro hidraulico para medicion de la evapotranspiracion potencial

English. A relatively economical hydrulic lysimeter was designed and installed in order to check its performance for measurement of potencial evapotranspiration. Three 57 cm-diameter and 88 cm-height cylindrical tanks were used as receptor containers of soil. In these tanks, Swazi grass (Digitaria swazilandensis) was sown. Like-hoop sensors were put under the tanks and connected to water manometers. Two of the lysimeters were used to measure evapotranspiration. In the third one, the loss or gain of water was interrupted in order to detect variations of the water level in its manometer because of the unique temperature effect and these variations were used to correct the lysimeter readings. The glasshouse experience proved the good stability of the lysimeter which showed its simplicity and easy use. The results demonstrated the good reliance of the responses of the apparatus. A value of 0,71 was found for the relationship between ETP and pan evaporation

Spanish; Castilian. Un lisimetro hidraulico relativamente economico fue disenado e instalado con el objeto de comprobar su funcionalidad para medir la evapotranspiracion potencial (ETP). Tres tanques cilindricos de 57 cm de diametro y 88 cm de altura se utilizaron como envases receptores de suelo; en ellos se sembro pasto pangola (Digitaria swazilandesis) y debajo se colocaron sensores en forma de aro, conectados cada uno a un manometro de agua. Dos de los lisimetros se usaron para medir evapotranspiracion y al tercero se le interrumpio la perdida o ganancia de agua, con el fin de detectar las variaciones del nivel de agua en su manometro por el solo efecto de la temperatura y mediante estas variaciones, poder corregir las lecturas. La experiencia en el invernadero demostro la buena estabilidad del lisimetro, asi como tambien su sencillez y facil manejo. Los resultados obtenidos demostraron buena contabilidad en las mediciones del aparato. Se encontro un valor de 0,71 para la relacion ETP/Evaporacion medida en tina.