| 摘要 |
PROBLEM TO BE SOLVED: To measure an AC erosion degree taking into consideration changes of soil resistance under cathode corrosion. SOLUTION: When acquiring soil resistance Rs between a sample pole We and verification pole Re, a current (lac') set at high frequency is applied to between a counter pole Ce and the sample pole We and the then AC voltage Vac is measured, and soil resistance Rs=Vac'/lac is acquired from an actual part Vac' of this measurement data and the applying current lac'. Next, a cathode current Idc' is applied to between the counter pole Ce and the sample pole We and this cathode current Idc' is gradually increased, and the applied cathode current Idc' is controlled so that an ON potential Vdc' of the then sample pole We to the verification pole Re is equal to a value (Vdc'=Idc'.Rs+ Vnet) which adds an IR dropping portion Idc'.Rs to a set value Vnet of an OFF potential Vnet, and the OFF potential Vnet in held and AC erosion is measured under cathode corrosion. |
