| 摘要 |
<p>The device is form the measurement of humidity in cultivation soil (2) and uses a pair of electrodes (13a,13b) pushed into the soil together with a current source and circuit for indirect feed of moisture into soil by application of alternating voltage over the electrodes, with feed of the produced current, with the aid of which the cultivation soil resistance is mesaured. The circuit is further arranged to compare the measured resistance with a predetermined threshold value. An alarm (6) produces a signal when the resistance exceeds the predetermined threshold value. The device incorporates a feed-in component (7), which activates the circuit to set the predetermined threshold value. This value is then stored in the circuit.</p> |
