Patent US4409080A successfully refreshed from Google Patents.
US4409080A
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System for monitoring a cathodically protected structure
Assignee: Texaco Inc
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Filing: 1981-06-18
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Granted: 1983-10-11
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Expires: 2001-06-18
Abstract
Abstract A corrosion monitoring system for measuring cathodic protection current flow. It is applicable to a buried structure that has cathodic protection applied to it. The monitoring system includes a microcoulometer connected between the buried structure and a small target electrode of a predetermined size.
Inventors
- 👤 Carlton M. Slough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:05
CPC Classifications
C; C23; C23F; C23F13/00; C23F13/02; C23F13/04; G; G01; G01R; G01R22/00; G01R22/02; G01R27/00; G01R27/02; G01R27/20
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
120 words
In a system having a buried structure being subject to galvanic corrosion, said structure being under cathodic protection comprising an anode and a DC power supply connected between said structure and said anode for counteracting said galvanic corrosion, means for monitoring the quantity of current flow between said anode and structure, comprising a microcoulometer having a precision capillary tube with two columns of mercury separated by an indicating gap of electrolyte, a target electrode having a predetermined relatively small surface area, said target electrode being buried spaced from one to fifteen feet from said buried structure, and a low resistance conductor connecting each of said two columns of mercury with one of said buried structure and said target electrode, respectively.
Claim 2
Dependent Claim
120 words
In a system having a buried structure being subject to galvanic corrosion, said structure being under cathodic protection comprising an anode and a DC power supply connected between said structure and said anode for counteracting said galvanic corrosion, means for monitoring the quantity of current flow between said anode and structure, comprising a microcoulometer having a precision capillary tube with two columns of mercury separated by an indicating gap of electrolyte, a target electrode having a predetermined relatively small surface area, said target electrode being buried spaced from one to fifteen feet from said buried structure, and a low resistance conductor connecting each of said two columns of mercury with one of said buried structure and said target electrode, respectively.
Claim 3
Dependent Claim
13 words
In a system according to claim 1, wherein said structure is a pipeline.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |