METHOD FOR MEASURING/EVALUATING CORROSION RISK OF CATHODICALLY-PROTECTED PIPELINE AND MEASURING/EVALUATING DEVICE

摘要

PROBLEM TO BE SOLVED: To accurately perform effect evaluation on alternating-current induction to prevent excessive countermeasures from being taken against alternating-current induction while appropriately determining the current range of a probe current to perform measurement with resolution allowing a sufficient collation with a cathodic protection standard, when finding probe current densities (probe DC current density I_DC and probe AC current density I_AC) to collate them with the protection standard.;SOLUTION: The probe current is measured by a probe current measuring means 10 which includes a low-pass filter 12 of a cut-off frequency larger than a commercial frequency and smaller than twice the commercial frequency and which has a current range set according to a difference between an acceptable maximum value and an acceptable minimum value of a probe current found from the cathodic protection standard. As to the measurement of the probe current within a unit measurement time period, an arithmetic processing means 20 determines whether or not all the measurement values are within the current range to judge the cathodic protection to be unsuccessful in cases where all the measured values are not within the current range.;COPYRIGHT: (C)2010,JPO&INPIT