| 摘要 |
<p>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 receiver 7 measures the signal to noise ratio, SNR, of the electromagnetic field 11 produced by the test current and if the SNR is below a threshold then the receiver 7 controls the transmitter 5 to set frequency and/or power characteristics of the test current.</p> |
