| 摘要 |
<p>Apparatus and method are provided for locating the position, depth, and run of a longitudinal metal object. Specifically, apparatus and method are provided for the tracing of a longitudinal subterranean metal object such as pipes or cables. The apparatus is capable of energizing a subterranean metal object and thereafter detecting the electromagnetic field produced by the metal object with a search loop. The magnitude of a current produced in the search loop is precisely measured whereby the location of the pipe or cable is precisely established. Circuitry is provided to provide high noise immunity to the detection of electromagnetic fields not originating with the metal object. Means are provided to maintain the system sensitivity without relying upon tedious mechanical adjustments.</p> |
