| 摘要 |
A ground water alert device includes an elongated water proof cable member which has a predetermined length and is inserted into a water level monitoring pipe of a well for a predetermined depth above a water table, a cable housing for delivering and collecting the cable member, a water sensor such as a probe which is electrically connected to a free end of the cable member for lowering into the monitoring pipe to the predetermined depth above the water table, a DC power source, a control circuitry electrically connected between the DC power source and the cable member for generating alert signals when the water sensor detects water, a depth indicator having a plurality of length scales uniformly provided along the cable member to indicate the length of the cable member from the water sensor, and a cable supporter for securing the cable member in place at a top end of the monitoring pipe so as to ensure the predetermined length of the cable member retaining in the monitoring pipe. The control circuitry comprises a function switch for electrically connecting with an alarm box by an alarm cable. The alarm box comprises at least an alarm signal device which would be activated to generate an alarm signal when the alarm box detects an electrical short while the water comes in contact with the water sensor or the water table rises to a predetermined safety level for any reason.
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