MONITORING METHOD AND DEVICE OF PIG POSITION, AND MONITORING METHOD OF PIPE MEMBER FOULING OR CORROSION

摘要

PROBLEM TO BE SOLVED: To provide a pig position monitoring method which enables a relatively simple and easy monitoring of the position of a pig which moves in a pipe member.;SOLUTION: Mobile sounds generated by the pig moving inside the pipe member are collected by a sound collecting microphone 6, the count of occurrences per unit time of sound components within the specific frequency range among the frequencies of the collected mobile sounds is counted by an arrangement for measuring frequency 20 to judge bent portions of the pipe member from the count of the occurrences per unit time, and monitor the position of the pig utilizing the bent portion information. The specific frequency range of the mobile sounds is in the frequency range of 800-1,200 Hz or less. When the pig moves on the bent portion of the pipe member, the pig moves as colliding against and contacting with the bent portion. Therefore, the mobile sounds contain many small components of the frequencies, and then, the count of the arrangement for measuring frequency 20 also increases.;COPYRIGHT: (C)2007,JPO&INPIT