摘要 |
A system 1 for detecting a buried conductor 3 comprises a transmitter 5 for producing an alternating test current in the buried conductor 3 and a receiver 7 for detecting an electromagnetic field 11 produced by the test current in the buried conductor 3. A communication link is provided between the receiver 7 and the transmitter 5. The test current comprises first and second components of different frequency. The receiver 7 monitors the phase creepage of the first and second components and controls the transmitter 7 to reset the phase difference between the first and second components as phase creepage increases.
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