Patent US4104579A successfully refreshed from Google Patents.
US4104579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of examination of protective coatings
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1976-03-15
•
Granted: 1978-08-01
•
Expires: 1996-03-15
Abstract
Abstract A method and assembly for detecting the presence of a failure in a protective coating on the surface of a metal body which comprises causing an electrolyte to make contact with the protective coating, and making comparison of the electric current generated through the electrolyte (a) between the metal body and a reference-electrode immersed in the electrolyte, and (b) between the same reference-electrode and a similation-electrode immersed in the electrolyte and having a working surface of the same metal as that of the metal body.
Inventors
- 👤 Malcolm Charles McIvor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:42
CPC Classifications
G; G01; G01N; G01N17/00; G01N17/02; G01N27/00; G01N27/26; G01N27/416; G01N27/49
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
94 words
A method for detecting the presence of a failure in a protective coating on the interior surface of a metal vessel which comprises causing an electrolyte to make contact with the protective coating, and making comparison of the electric current generated through the electrolyte (a) between the metal vessel and a reference-electrode immersed in the electrolyte, and (b) between the same reference electrode and a simulation-electrode immersed in the electrolyte and having a working surface of the same metal as that of the metal vessel said reference electrode and simulation-electrode simultaneously contacting said electrolyte.
Claim 2
Independent Claim
94 words
A method for detecting the presence of a failure in a protective coating on the interior surface of a metal vessel which comprises causing an electrolyte to make contact with the protective coating, and making comparison of the electric current generated through the electrolyte (a) between the metal vessel and a reference-electrode immersed in the electrolyte, and (b) between the same reference electrode and a simulation-electrode immersed in the electrolyte and having a working surface of the same metal as that of the metal vessel said reference electrode and simulation-electrode simultaneously contacting said electrolyte.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1 in which the working surface of the reference-electrode is chemically inert to the electrolyte.
Claim 4
Dependent Claim
17 words
A method as described in claim 2 in which the reference-electrode is made of a noble metal.
Claim 5
Dependent Claim
14 words
A method as claimed in claim 3 in which the noble metal is platinum.
Claim 6
Dependent Claim
41 words
A method as claimed in claim 1 for detecting the presence of a failure in a protective coating on the surface of a mild steel vessel, in which at least the working surface of the simulation-electrode is made of mild steel.
Claim 7
Dependent Claim
21 words
A method as claimed in claim 1 in which the electrolyte is an aqueous solution of an acid, base or salt.
Claim 8
Dependent Claim
74 words
A method as claimed in claim 1 wherein subsequent to detection of the presence of a failure in the protective coating, the approximate location of a failure is determined by progressively removing the electrolyte from areas of the protective coating until the comparison of electric currents indicates that a failure no longer exists in the protective coating so that the failure exists in that area of the coating from which electrolyte has been removed.
Claim 9
Dependent Claim
100 words
A probe assembly for detecting the presence of a failure in a protective coating on the surface of a metal vessel comprising a reference-electrode having a working surface chemically inert to electrolyte and a simulation-electrode having a working surface of the same metal as that of the vessel, the electrodes being disposed so that their working surfaces may contact simultaneously an electrolyte contained in the vessel, and an electrical circuit containing a meter, a switch adapted so that the reference electrode may be connected via the meter either directly to the simulation-electrode or to the metal body of the vessel.
Claim 10
Dependent Claim
100 words
A probe assembly for detecting the presence of a failure in a protective coating on the surface of a metal vessel comprising a reference-electrode having a working surface chemically inert to electrolyte and a simulation-electrode having a working surface of the same metal as that of the vessel, the electrodes being disposed so that their working surfaces may contact simultaneously an electrolyte contained in the vessel, and an electrical circuit containing a meter, a switch adapted so that the reference electrode may be connected via the meter either directly to the simulation-electrode or to the metal body of the vessel.
Claim 11
Dependent Claim
21 words
A probe assembly as described in claim 8 wherein the working surface of the reference-electrode is made of a noble metal.
Claim 12
Dependent Claim
14 words
A probe assembly as claimed in claim 9 wherein the noble metal is platinum.
Claim 13
Dependent Claim
49 words
A probe assembly as claimed in claim 8 for detecting a failure in a protective coating on the surface of a vessel made of more than one metal which contains more than one simulation-electrode, each simulation-electrode having a working surface made of one of the metals of the vessel.
Claim 14
Dependent Claim
32 words
A probe assembly as claimed in claim 8 wherein the switches are adapted so that the reference-electrode may also be connected indirectly to the simulation-electrode via the metal body of the vessel.
Claim 15
Dependent Claim
39 words
A probe assembly as claimed in claim 8 for detecting the presence of a failure in a protective coating on the surface of a mild steel vessel wherein the working surface of the simulation-electrode is made of mild steel.
References Cited (Backward Citations)
US2457234A
Cited
US2869003A
Cited
US3250689A
Cited
US3696017A
Cited
US3858114A
Cited
US3831085A
Cited
US3965415A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-31 | 1982-01-30 | 1982-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-31 | 1986-01-30 | 1986-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-31 | 1990-01-30 | 1990-08-01 | $7700.00 | Window Closed / Lapsed |