Patent US4473456A successfully refreshed from Google Patents.
US4473456A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conductimetric gas sensor
Assignee: NATIONAL RESEARCH DEVELOPMENT Corp 66-74 VICTORIA ST LONDON SW1 ENGLAND A BRITISH CORP
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Filing: 1982-03-22
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Granted: 1984-09-25
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Expires: 2002-03-22
Abstract
Abstract A conductimetric gas sensor consists of a ptfe body forming an electrolytic cell; two threaded silver electrodes screwed into the ptfe body and bridged by a layer of a hydrophilic gel in contact with an electrolyte in the cell; a reservoir for supplying deionized water to the cell, so that the volume of water between the electrodes is maintained; and a gas-permeable hydrophobic layer through which the hydrophilic gel can be exposed to the gas.
Inventors
- 👤 Peter Hawkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:45
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/4162
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
95 words
A conductimetric gas sensor, for measurement of gas concentration in a static or flowing fluid, comprising: an electrolytic cell for containing an electrolyte of deionised water; a gas-permeable hydrophobic layer through which a gas to be sensed can contact said electrolyte contained in the cell; two spaced electrodes within the cell and both closely adjacent the gas-permeable hydrophobic layer; between the electrodes and the hydrophobic layer, a layer of a hydrophilic gel of polymeric material; and a reservoir supplying deionised water to the cell, so that the volume of water between the electrodes is maintained.
Claim 2
Dependent Claim
95 words
A conductimetric gas sensor, for measurement of gas concentration in a static or flowing fluid, comprising: an electrolytic cell for containing an electrolyte of deionised water; a gas-permeable hydrophobic layer through which a gas to be sensed can contact said electrolyte contained in the cell; two spaced electrodes within the cell and both closely adjacent the gas-permeable hydrophobic layer; between the electrodes and the hydrophobic layer, a layer of a hydrophilic gel of polymeric material; and a reservoir supplying deionised water to the cell, so that the volume of water between the electrodes is maintained.
Claim 3
Dependent Claim
13 words
A sensor according to claim 1 in which the hydrophilic gel is polyacryloylmorpholine.
Claim 4
Dependent Claim
16 words
A sensor according to claim 1 in which the gas permeable hydrophobic layer is polytetrafluoroethylene film.
Claim 5
Dependent Claim
29 words
A sensor according to claim 1 in which the electrolyte cell is a polytetrafluoroethylene body and the two electrodes are threaded silver rods which are screwed into said body.
Claim 6
Dependent Claim
26 words
A sensor according to claim 1 further comprising conductivity sensing means arranged to sense the electrical conductivity of the electrolyte in the cell between the electrodes.
Claim 7
Dependent Claim
32 words
A sensor according to claim 1 in which the hydrophilic gel includes an enzyme material capable of reducing the response time of the sensor to both increases and decreases in gas concentration.
Claim 8
Dependent Claim
13 words
A sensor according to claim 6 in which the enzyme is carbonic anhydrase.
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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) | 1987-09-25 | 1988-03-26 | 1988-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-25 | 1992-03-26 | 1992-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-25 | 1996-03-26 | 1996-09-25 | $7700.00 | Window Closed / Lapsed |