| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a system for controlling cathodic protection for a buried pipeline by connecting pipelines having different corrosion protection conditions through an insulation joint and applying the cathodic protection on either or both of the connected pipelines, which reduces a risk of alternating-current corrosion when a large alternating induction voltage has occurred in both pipelines, and also can grasp whether the pipelines that are objects of corrosion protection are under appropriate cathodic protection conditions or not by clarifying an effect of a corrosion-protecting current on reducing corrosion in each pipeline; or a method for controlling the cathodic protection. <P>SOLUTION: This control method includes: connecting an input terminal 10A of such an inverting amplifier 10 that the amplification factor becomes -1 time, to one of the pipelines L1 and L2 which have been connected through the insulation joint 1; connecting an output terminal 10B of the inverting amplifier 10 to the other of the pipelines L1 and L2; and connecting a pair of diodes 14 and 15 having the same voltage-current characteristics reversely in parallel between an inverting input terminal 11B and the output terminal 10B in the inverting amplifier 10. <P>COPYRIGHT: (C)2011,JPO&INPIT |
