APPARATUS AND METHOD FOR MONITORING COATING DAMAGE ON UNDERGROUND PIPE

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for monitoring coating damage by using frequencies in which presence or absence of coating damage and its location are easier to determine even on a long pipe and the number of measuring instruments for determining the damaged section can be reduced. SOLUTION: A monitoring apparatus 100 for coating damage on an underground pipe comprises: a signal transmitter 20 for transmitting an asynchronous pseudo-random signal with a plurality of fundamental frequencies from at least one transmission location 12 on the underground pipe 10; a receiver 30 for receiving the asynchronous pseudo-random signal at the transmission location 12; a receiver 40 for receiving the asynchronous pseudo-random signal at a distant location on the underground pipe from the transmission location 12; and a computer 50 for monitoring the pipe-to-ground potential and energization current and monitoring coating damage occurrence and its section on the underground pipe based on changes in the ground resistance and the pipe-to-ground potential of the underground pipe due to changes in the correlation peak value of the asynchronous pseudo-random signal with the plurality of fundamental frequencies. COPYRIGHT: (C)2009,JPO&INPIT