US4658365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for in-situ monitoring of corrosion rate of cathodically polarized metals
Assignee: Electric Power Research Institute
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Filing: 1984-02-02
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Granted: 1987-04-14
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Expires: 2004-02-02
Abstract
Abstract A method of monitoring the rate of corrosion of a cathodically protected system, comprising superimposing a sinusoidal voltage on a cathodic protection voltage imposed on a portion of the system, measuring an anodic dissolution current in response to the superimposed voltage, and calculating the corrosion rate from the anodic dissolution current at the cathodic protection voltage potential.
Inventors
- 👤 Barry C. Syrett
- 👤 Michael C. H. McKubre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:02
CPC Classifications
G; G01; G01N; G01N17/00; G01N17/02; C; C23; C23F; C23F13/00; C23F13/02; C23F13/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
92 words
A method of monitoring the rate of corrosion of a cathodically protected system, comprising superimposing a sinusoidal voltage on a cathodic protection voltage imposed on a portion of the system, measuring an anodic dissolution current in response to the superimposed voltage at each of a plurality of harmonics of said anodic dissolution current, including measuring a rectification current which comprises the DC response of the anodic dissolution current to the presence of said superimposed sinusoidal voltage; and calculating the corrosion rate from the anodic dissolution current at the cathodic protection voltage potential.
Claim 2
Independent Claim
92 words
A method of monitoring the rate of corrosion of a cathodically protected system, comprising superimposing a sinusoidal voltage on a cathodic protection voltage imposed on a portion of the system, measuring an anodic dissolution current in response to the superimposed voltage at each of a plurality of harmonics of said anodic dissolution current, including measuring a rectification current which comprises the DC response of the anodic dissolution current to the presence of said superimposed sinusoidal voltage; and calculating the corrosion rate from the anodic dissolution current at the cathodic protection voltage potential.
Claim 3
Dependent Claim
27 words
A method as claimed in claim 1 wherein said sinusoidal voltage is at frequency f, said response being measured at regular harmonics h of the response frequencies.
Claim 4
Dependent Claim
18 words
A method as claimed in claim 2 wherein the harmonic current response is measured at n·h for n=0,1,2,3,4,5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |