US4040931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion ratemeter
Assignee: Baker Petrolite LLC
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Filing: 1976-08-16
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Granted: 1977-08-09
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Expires: 1996-08-16
Abstract
Abstract An improvement to an automatic correcting type of corrosion ratemeter (e.g., U.S. Pat. No. 3,717,566) with test specimen, reference and third electrodes in contact with corrodant and "null" and "measurement" circuitry whereby correcting is made for freely corroding potential and addition of reference polarization potential between the test and reference electrodes in conjunction with controlled current flow between the test and third electrodes. The improvement comprises unique circuitry for common base, steady state readouts eliminating asynchronous cycle time problems and providing precise simultaneous readout(s) calibration.
Inventors
- 👤 Homer M. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:42
CPC Classifications
G; G01; G01N; G01N17/00; G01N17/02
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
212 words
In a corrosion ratemeter having reference, test and third electrodes adapted to be placed into contact with a corrodant, a voltage loop circuit including a voltage comparator connecting said reference and test electrodes, a current loop circuit including a current source means connecting said test and third electrodes, signal correction means and reference signal means associated with said voltage and current loops for freely corroding potential correction and polarization potential addition therein and current-to-voltage converting means in said current loop provide a voltage signal proportional to current flow in said current loop; the improvement comprising: a. first capacitance means connected with said current-to-voltage converting means for storing a first voltage proportional in magnitude to said voltage signal; b. storage means having a second capacitance means with a second voltage therein; and c. means for periodically connecting the first capacitance means across the storage means whereby the second capacitance means stores a resultant voltage, which resultant voltage is in proportion to the first voltage by the capacitance ratio of the first capacitance means to the sum of the first and second capacitance means, and summed with the second voltage on the second capacitance means by the capacitance ratio of the second capacitance means to the sum of the first and second capacitance means.
Claim 2
Dependent Claim
212 words
In a corrosion ratemeter having reference, test and third electrodes adapted to be placed into contact with a corrodant, a voltage loop circuit including a voltage comparator connecting said reference and test electrodes, a current loop circuit including a current source means connecting said test and third electrodes, signal correction means and reference signal means associated with said voltage and current loops for freely corroding potential correction and polarization potential addition therein and current-to-voltage converting means in said current loop provide a voltage signal proportional to current flow in said current loop; the improvement comprising: a. first capacitance means connected with said current-to-voltage converting means for storing a first voltage proportional in magnitude to said voltage signal; b. storage means having a second capacitance means with a second voltage therein; and c. means for periodically connecting the first capacitance means across the storage means whereby the second capacitance means stores a resultant voltage, which resultant voltage is in proportion to the first voltage by the capacitance ratio of the first capacitance means to the sum of the first and second capacitance means, and summed with the second voltage on the second capacitance means by the capacitance ratio of the second capacitance means to the sum of the first and second capacitance means.
Claim 3
Dependent Claim
20 words
The corrosion ratemeter of claim 1 further including readout means receiving said resultant voltage to provide an output indicative thereof.
Claim 4
Dependent Claim
18 words
The corrosion ratemeter of claim 2 wherein said readout means includes recorders, alarm circuitry and current transmitter means.
Claim 5
Dependent Claim
23 words
The corrosion ratemeter of claim 3 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 6
Dependent Claim
81 words
The corrosion ratemeter of claim 2 wherein said storage means has an output connected at one corner of four arm impedance balanced electrical bridge with the opposite corner thereof at circuit common relative to a source of d.c. potential connected into the bridge, and the bridge output to said readout means is taken across an arm of said bridge whereby said bridge output is proportional to the sum of the output of the storage means and the source of d.c. potential.
Claim 7
Dependent Claim
23 words
The corrosion ratemeter of claim 5 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 8
Dependent Claim
53 words
The corrosion ratemeter of claim 2 wherein said readout means is a current transmitter means receiving said resultant voltage, said current transmitter means comprising an amplifier receiving said resultant voltage as an input and providing an output signal to a current amplifier means having an output current signal proportional to said resultant voltage.
Claim 9
Dependent Claim
52 words
The corrosion ratemeter of claim 7 wherein said current transmitter means receives said resultant voltage biased by an offset voltage from a voltage source means whereby said output current signal is offset from zero magnitude of said resultant voltage by a certain percentage of the maximum magnitude of said output current signal.
Claim 10
Dependent Claim
23 words
The corrosion ratemeter of claim 8 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 11
Dependent Claim
33 words
The corrosion ratemeter of claim 7 wherein said current amplifier means includes voltage to current proportioning means whereby said output current signal can be adjusted independently in proportion to said resultant voltage signal.
Claim 12
Dependent Claim
42 words
The corrosion ratemeter of claim 10 wherein said current amplifier means is a power transistor being base driven from said amplifier through a field effect transistor having selectable gate biasing for limiting the magnitude of said output signal from said power transistor.
Claim 13
Dependent Claim
23 words
The corrosion ratemeter of claim 11 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 14
Dependent Claim
23 words
The corrosion ratemeter of claim 10 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 15
Dependent Claim
23 words
The corrosion ratemeter of claim 7 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 16
Dependent Claim
49 words
The corrosion ratemeter of claim 2 wherein said readout means includes an alarm circuit means receiving said resultant voltage as one input with a second input at a set point voltage signal and having an output circuit including contactor means adapted to complete one or more alarm signal circuits.
Claim 17
Dependent Claim
23 words
The corrosion ratemeter of claim 15 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 18
Dependent Claim
43 words
The corrosion ratemeter of claim 1 wherein said storage means has an output connected at one corner of four arm impedance balanced electrical bridge with the opposite corner thereof at circuit common relative to a source of d.c. potential connected into the bridge.
Claim 19
Dependent Claim
23 words
The corrosion ratemeter of claim 17 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 20
Dependent Claim
23 words
The corrosion ratemeter of claim 2 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
Claim 21
Dependent Claim
23 words
The corrosion ratemeter of claim 1 wherein said means for periodically connecting the first capacitance means across the storage means is switch means.
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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |