| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for detecting the damage to a corrosion-proof coating precisely without being restricted by the installation environment or the like of a detector, and provide the detector for the method. SOLUTION: The detector 100 for detecting the damage to the corrosion-proof coating is equipped with a paired electrode 18 embedded in the ground, a transmitter 23 for passing an AC current across metal piping 19, which has the corrosion-proof coating 20 applied to its outer surface, embedded in the ground and the paired electrode 18, wheel electrodes 1 movable on the surface of the ground just above the piping 19, a receiver 13 for synchronously detecting the potential difference signal of the surface of the ground obtained by detecting the potential difference by the wheel electrodes 1. The receiver 13 has a coil 2 for detecting a magnetic field yielded by passing the AC current through the piping 19 and uses the magnetic field detected by the coil as a reference signal in the synchronous detection of the potential difference signal. COPYRIGHT: (C)2004,JPO&NCIPI |
