| 摘要 |
<p>An automatic irrigation regulator comprises an evaporation pan 19 provided with means for sensing the water level in the pan and for controlling irrigation means, the sensing means also controlling means for supplying the pan with an amount of water equal to that lost by evaporation. Preferably the sensing means comprises a float 14 which houses a ring magnet for controlling a valve 11. Opening of valve 11 allows flow of water into the pan 19 and also causes a valve 13 to open to supply irrigation water. In a preferred embodiment a system of such regulators (Figs. C, D, E) is arranged so that not all may be active to deliver water at the same time. <IMAGE></p> |
