| 摘要 |
PURPOSE:To search buried position of an underground cable with high accuracy removing the disturbance caused by buried metallic body around here by measuring the ground surface magnetic field with plurality of search coils attached to a frame having a matrix construction. CONSTITUTION:A frame 2 is set straddling a cable buried position so that it may be approximiately right angle to the buried direction thereof. Then, the frame 2 is moved horizontally and fixed initially at a point where magnetic field intensity signals of searh coils 3a, 3b, and 3c mounted horizontally to the frame. Then, detecting signals of search coils 4a-21a designed at arbitrary angles are selected by a scanning part 27, amplified selectively in order, input to a coil rotation cotrolling part 30 and control the angle of the coil so that an induced voltage of the search coil may be min. This angle shows a direction of the magnetic field in this point and an output of each of search coils 4b-21b perpendicular to this shows a magnetic intensity. The buried position of the cable can be confirmed by the selection of the output of efficacious coil group having a fluxity even if there exists another buried material in its neighbourhood. |
