| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electric protection method for a water pipe where over-protection can be prevented, and a suitable protection state can be easily and stably held. <P>SOLUTION: According to the invention, an anode 2 is connected to an anode terminal 30 in a power device 3 so as to be conductible, and is arranged at the inside of a water pipe 1, further, the water pipe 1 is used as a cathode, and is connected to a cathode terminal 31 in the power device 3 so as to be conductible, and protection current is made to flow from the power device 3, performing corrosion protection of the water pipe 1. Electric current is made to flow between the cathode 1 and the anode 2 till a state wherein the polarization of the cathode 1 and the anode 2 is made almost constant, and, based on the interpole voltage difference obtained by reducing the voltage difference almost made constant between the anode 2 and the cathode 1 after a prescribed time from the cut off of the conduction or the voltage difference made almost the minimum from the initial instant off voltage between the anode 2 and the cathode 1 at the time when the conducting is cut off, the protection applying voltage to be applied from the power device 3 to the anode 2 and the cathode 1 at the time when the protection current is made to flow is set. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
