| 摘要 |
PROBLEM TO BE SOLVED: To simplify work, to reduce the number of workers, and to allow measurement on a graveled road or a lawn. SOLUTION: A coating film damage detector is provided with an electric cart 10, wheel-shaped sensors 23a, 23b detecting a ground surface potential of a buried coated steel pipe 1 to which alternating voltage is impressed between an earth electrode in the ground and it, a water tank 21 mounted to the electric cart 10, a header 26 supplying water inside the water tank 21 to the outer circumference parts of the wheel-shaped sensors 23a, 23b, and a signal processor 22 finding a potential difference distribution on the ground surface on the basis of the outputs from a pair of wheel-shaped sensors 23a, 23b and detecting a damaged position in the buried coated steel pipe 1 on the basis of the potential difference distribution. The coating film damage detector is also provided with another pair of wheel-shaped sensors and a frame body fixing and supporting the wheel-shaped sensors, and the outputs of the pair of wheel-shaped sensors are outputted to the signal processor 22.
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