Title:
METHOD AND DEVICE FOR MEASURING AC EROSION DEGREE UNDER NATURAL POTENTIAL AND CATHODE CORROSION
Document Type and Number:
Japanese Patent JP3632877
Kind Code:
B2
Abstract:
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.
Inventors:
Fumio Kajiyama
Application Number:
JP3735697A
Publication Date:
March 23, 2005
Filing Date:
February 21, 1997
Export Citation:
Assignee:
Tokyo Gas Co., Ltd.
International Classes:
G01N17/02; C23F13/00; G01N27/26; (IPC1-7): G01N27/26; C23F13/00; G01N17/02
Domestic Patent References:
| JP2008733A | ||||
| JP58208654A | ||||
| JP6341967A |
Other References:
D. Funk,Investigation of AC corrosion in cathodically protected pipes,3R International,1992年,Vol.31,No.6,336-341
西方篤,陰極防食された炭素鋼の交流インピーダンス特性と最適防食電位,防食技術,1987年,Vol.36,No.1,23-26
西方篤,陰極防食された炭素鋼の交流インピーダンス特性と最適防食電位,防食技術,1987年,Vol.36,No.1,23-26
Attorney, Agent or Firm:
Hiroshi Ohashi
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