US3661748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fault sensing instrumentation
Assignee: Honeywell International Inc
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Filing: 1970-04-07
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Granted: 1972-05-09
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Expires: 1990-04-07
Abstract
Abstract An electrochemical sensor system includes an electrode assembly that produces a DC signal as a function of a parameter of interest sensed by the electrode system. An AC signal is applied via an electrode to the conductor fluid in which the electrode system is disposed and an AC signal detector is connected to the DC circuitry. A threshold circuit responsive to the output of the AC signal detector indicates fault in the electrochemical sensor system whenever the AC signal detector has an output of predetermined magnitude.
Inventors
- 👤 David E Blackmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:17
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/416; G01N27/4163; G01N33/00; G01N33/48; G01N33/483; G01N33/487; G01N33/49; G01N33/4925
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
26 words
The system as claimed in claim 1 and further including means for applying a reference signal from said AC signal source to said phase sensitive detector.
Claim 2
Dependent Claim
33 words
The system as claimed in claim 1 wherein said phase sensitive detector includes means for discriminating against the capacitive component of the AC signal passed through said DC circuitry from said electrode system.
Claim 3
Dependent Claim
23 words
The system as claimed in claim 1 and further including means responsive to said threshold circuit output signal for producing a control function.
Claim 4
Dependent Claim
154 words
An electrochemical sensor system having an electrode system for disposition in a conductive fluid and arranged to produce a DC signal as a function of a parameter of interest sensed by said electrode system, said electrode system including an active electrode and a reference electrode, DC circuitry responsive to said DC signal for producing an output indicative of the parameter of interest being sensed by said electrode system, an impedance network connected to said reference electrode, said impedance network determining a threshold value, means for providing an electrical connection to said conductive fluid, means to apply an AC signal to said electrical connection, an AC signal detector connected to said DC circuitry, and a thReshold circuit responsive to the output of said AC signal detector for providing an output signal indicative of fault in said electrochemical sensor system when said AC signal detector has an output of predetermined value relative to said threshold value.
Claim 5
Dependent Claim
168 words
An electrochemical sensor system having an electrode system for disposition in a conductive fluid and arranged to produce a DC signal as a function of a parameter of interest sensed by said electrode system, said electrode system including an anode electrode and a cathode electrode, DC circuitry responsive to said DC signal for producing an output indicative of the parameter of interest being sensed by said electrode system, said DC circuitry including an operational amplifier of the trans-resistance type, an AC gain network connected in the feedback loop of said operational amplifier for establishing a threshold level, means for providing an electrical connection to said conductive fluid, means to apply an AC signal to said electrical connection, an AC signal detector connected to said DC circuitry, and a threshold circuit responsive to the output of said AC signal detector for providing an output signal indicative of fault in said electrochemical sensor system when said AC signal detector has an output of predetermined value relative to said threshold level.
Claim 6
Dependent Claim
167 words
An electrochemical sensor system having an electrode system for disposition in a conductive fluid and arranged to produce a DC signal as a function of a parameter of interest sensed by said electrode system, said electrode system including a pH electrode and a reference electrode, DC circuitry including a differential amplifier responsive to said DC signal for producing an output indicative of the parameter of interest being sensed by said electrode system, an AC signal detector connected to said DC circuitry, means for applying an AC signal to said reference electrode, a difference network connected between the outputs of said pH and reference electrodes for applying a difference signal to said AC signal detector, the component values in said difference circuitry determining a threshold value and a threshold circuit responsive to the output of said AC signal detector for providing an output signal indicative of fault in said electro-chemical sensor system when said AC signal detector has an output of predetermined value relative to said threshold value.
References Cited (Backward Citations)
US3345273A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |