| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a system for achieving proper cathodic protection of pipes in a pipeline in which dissimilar metal pipes such as a steel pipe and a cast iron pipe are intermingled. <P>SOLUTION: A galvanic anode 1 is connected to a first metal pipe P1. A bond current circuit 3 for producing bond current flowing between the first metal pipe and a second metal pipe P2 is connected in parallel to an insulated joint IJ. A bond current regulating means 30 and a circuit cutoff means 31 for turning on and off the bond current circuit are connected in series to the bond current circuit. The bond current circuit is turned off by the circuit cutoff means in the state where the current generated in the galvanic anode is subjected to constant current control to thereby measure the instant-off potential of the second metal pipe. One or both of the starting voltage of the bond current regulating means and the current generated in the galvanic anode are set so that the difference between the spontaneous potential and the instant-off potential of the second metal pipe may be equal to a reference value or more. <P>COPYRIGHT: (C)2012,JPO&INPIT |
