US4160171A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining the reference voltage in an impressed current corrosion protection system
Assignee: Harco Corp
•
Filing: 1977-08-05
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Granted: 1979-07-03
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Expires: 1997-08-05
Abstract
Abstract Method and apparatus for determining the true cathode polarization potential or reference voltage for any corrosion protection system and which determination may be visually indicated, used as a feedback for automatic control of the corrosion protection system or both.
Inventors
- 👤 Larry H. Merrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:57
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/0084; C; C23; C23F; C23F13/00; C23F13/02; C23F13/04; G01N; G01N17/00; G01N17/02; G01R17/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
217 words
A method of continuously determining the natural reference voltage in an impressed current corrosion protection system having cyclic pulses of direct current for retarding undesired corrosion including the steps of: sensing continuously the voltage present in the electrolyte of the corrosion protection system with a reference electrode; producing a continuous electrical signal as a function of the sensed voltage; passing the electrical signal into two separate conductive paths; conducting the electrical signal in one conductive path to a summing amplifier without change to the electrical signal; filtering the direct current voltage from the electrical signal through a capacitor in the second conductive paths to provide a resulting electrical signal that is a function of the fluctuating voltage drop of the sensed impressed current resistance of the corrosion protection system; amplifying the filtered electric signal that is a function of the fluctuating voltage drop of the impressed current resistance to provide an electrical signal of a constant polarity in the second conductive path; inverting the filtered and amplified electrical signal of a constant polarity in the second conductive path; and combining the separate signals in the two conductive paths algebraically at the summing amplifier to obtain an output signal from the summing amplifier that is a function of only the natural reference voltage of the cathodic protection system.
Claim 2
Independent Claim
217 words
A method of continuously determining the natural reference voltage in an impressed current corrosion protection system having cyclic pulses of direct current for retarding undesired corrosion including the steps of: sensing continuously the voltage present in the electrolyte of the corrosion protection system with a reference electrode; producing a continuous electrical signal as a function of the sensed voltage; passing the electrical signal into two separate conductive paths; conducting the electrical signal in one conductive path to a summing amplifier without change to the electrical signal; filtering the direct current voltage from the electrical signal through a capacitor in the second conductive paths to provide a resulting electrical signal that is a function of the fluctuating voltage drop of the sensed impressed current resistance of the corrosion protection system; amplifying the filtered electric signal that is a function of the fluctuating voltage drop of the impressed current resistance to provide an electrical signal of a constant polarity in the second conductive path; inverting the filtered and amplified electrical signal of a constant polarity in the second conductive path; and combining the separate signals in the two conductive paths algebraically at the summing amplifier to obtain an output signal from the summing amplifier that is a function of only the natural reference voltage of the cathodic protection system.
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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) | 1982-07-02 | 1983-01-01 | 1983-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-02 | 1987-01-01 | 1987-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-02 | 1991-01-01 | 1991-07-03 | $7700.00 | Window Closed / Lapsed |