DAMAGE POSITION DETECTING METHOD FOR INTERNAL SURFACE COATING OF BURIED PIPE

摘要

PURPOSE:To detect a damage position in a lining layer on the internal surface of a buried pipe by positioning a self-running car equipped with two detection electrodes inside the lining layer. CONSTITUTION:The self-running car equipped with the two detection electrodes 3 and 4 at a prescribed interval is positioned at the inside of the buried pipe 1 which has the lining layer 2 on its internal surface. Then a conductive liquid 6 is charged to the inside of the lining layer 2 and an electrode 8 connected to one terminal of a power source 7 is dipped in this conductive liquid 6. The other terminal 9 of the power source 7, on the other hand, is grounded and the potential between the two detection electrodes 3 and 4 is measured. If the lining layer 2 damages, the electrode 8 and the other terminal 9 of the power source 7 conducts with a certain resistance value and the potential in the conductive liquid 6 shows a specific distribution state. Consequently, the conduction state between the conductive liquid 6 and the side of the buried pipe 1 due to the local rupture of the lining layer 2 can be detected and the rupture position of the lining layer 2 is made clear.