| 摘要 |
PROBLEM TO BE SOLVED: To precisely detect a minute scratch on a pipe inner peripheral surface without being affected from a plumbing state by causing disturbance in an air flow on a periphery of a scratch caused on the pipe inner peripheral surface and notifying the presence of the scratch based on the detection information of the disturbance of the air flow. SOLUTION: An air nozzle 21 is connected to an air pump 31 through a flexible tube 35, and is inserted into the inside of the pipe, and jets out air from the air pump 31 to the pipe inner peripheral surface to form an air flow in the pipe, and causes the disturbance in the air flow on the periphery of the scratch caused on the pipe inner peripheral surface. A microphone 22 detects the disturbance in the air flow caused on the periphery of the scratch of the pipe inner peripheral surface as a change of a frequency, and a scratch detector 32 detects the presence of the scratch on the pipe inner peripheral surface based on the information of the frequency collected by the microphone 22. Then, a speaker 33 and a monitor 34, etc., inform an inspector of the presence of the scratch on the pipe inner peripheral surface from the detection result by the scratch detector 32. |
