METHOD FOR DETECTING COATING DAMAGE POSITION OF BURIED TUBE

摘要

PURPOSE:To detect the coating damage position of a buried tube by measuring a potential difference at specific angle intervals while positioning one of two detection electrodes on the ground surface above the coating damage part of the buried tube and moving the other on the concentric circle of the detection electrode. CONSTITUTION:One electrode 3 of a power source is connected to the buried tube 1, and the two detection electrodes 6 and 7 which are arranged at a specific interval are inserted into the ground surface above the buried tube to detect the position where the potential difference between the electrodes 6 and 7 is minimum. While the electrode 6 is positioned right above the buried tube 1 at the position where the difference is minimum and the electrode 7 is moved on the concentric circle of the electrode 6, the potential difference is measured at the specific angle intervals and the results are recorded on a radar chart. Here, the part where the potential is smallest on the radar chart is detected as the coating damage position of the buried tube.