METHOD AND APPARATUS FOR DIAGNOSING CORROSION OF UNDERGROUND PIPELINE

摘要

PURPOSE:To improve the inspection speed and inspection operability, by diagnosing the corrosion of an underground buried pipeline noncontact using an electromagnetic ultrasonic wave. CONSTITUTION:A rotary unit 2 and a driver 3 are self-driven by the driver 3 and moves through a pipeline 7 to be set at a measuring point. An electromagnetic ultrasonic sensor 11 is started with a transmitter/receiver 4a to excite an incident wave 14 and a bottom surface echo 12 or a defect echo 13 are received. The echo signal thus obtained is converted into an electrical signal and sent to an arithmetic unit 4 through the transmitter/receiver 4a to calculate thickness at the measuring point from the difference in the reception time. Likewise, this apparatus is moved from measuring point to determine the thickness at various measuring points by repeating measurement and the minimum thickness and the position thereof are found out. A display/recorder 5 connects thickness values at various measuring points to calculate the corroded part 27 and the area thereof by 2-D plotting and displays and records the results.