ABNORMAL LOW GROUNDING SPOT DETECTION METHOD AND DETECTION SYSTEM OF BURIED METAL PIPELINE

摘要

PROBLEM TO BE SOLVED: To detect an abnormal low grounding spot of a buried metal pipeline to which a bituminous coating is applied.;SOLUTION: This system is equipped with: an electrode installed close to one end of a detection object section set on a ground part just above a burying position, by confirming the burying position of a cathode-protected buried metal pipeline to which a bituminous coating is applied; a DC power supply device connected between the electrode and the buried metal pipeline so that a protective current is generated from the electrode; a control/measuring means for measuring a pipe-to-ground potential of the buried metal pipeline on each spot in the detection object section, while repeating the on/off state of the DC power supply device, and measuring a ground surface potential difference between unit two spots; and a detection means for detecting the abnormal low grounding spot of the buried metal pipeline, based on a change on each measuring spot of the pipe-to-ground potential corresponding to the on/off state of the DC power supply device and on a change on each measuring spot of the ground surface potential difference when the DC power supply device is in the on-state.;COPYRIGHT: (C)2008,JPO&INPIT