| 摘要 |
<p>Pairs of electrodes buried in pits filled with coarse sand or stone chippings, near the tank or pipe line from which leakage is to be detected, are connected in a bridge circuit which is balanced under normal conditions. A change in the resistance between any pair of electrodes, brought about an oil leakage which results in a sudden rise triggers an alarm circuit as a result of the bridge unbalance.</p> |
