US4197177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for analysis of nitrogen oxides
Assignee: Individual
•
Filing: 1978-05-22
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Granted: 1980-04-08
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Expires: 1998-05-22
Abstract
Abstract Apparatus for analyzing the concentration of nitrogen oxides in a gas draws the gas through three separate housings in succession. Moisture is removed from the gas in the first housing and an oxidizing agent in the second chamber converts the nitrogen oxides in the dried gas into nitrogen dioxide. The third housing contains an electrolytic cell producing an electric signal proportional to the concentration of nitrogen dioxide in the converted gas. The electrolytic cell has an anode of activated carbon in a perforated jacket located in a neutral electrolyte and a cathode contacted by the converted gas. The cathode is composed of platinum tape wound onto a support. A sheath of glass fibres contacts both the cathode and the electrolyte and lifts the electrolyte by capillary action to wet the cathode.
Inventors
- 👤 Albert E. Proctor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:04
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/4045; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0011; G01N33/0027; G01N33/0036; G01N33/0037; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/177692
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
138 words
In an apparatus for use in analysing the concentration of nitrogen oxides in a gas; said apparatus including means for converting nitrogen oxides in the gas to be analysed into nitrogen dioxide and an electrolytic cell for producing an electrical signal proportional to the concentration of the nitrogen dioxide in the converted gas; the improvement comprising an electrolytic cell containing a neutral aqueous electrolyte in a sealed chamber; an anode in said sealed chamber comprising activated carbon within a perforated jacket immersed in said electrolyte; a cathode in said sealed chamber comprising a platinum element supported above the electrolyte for direct contact with the converted gas; and capillary means in said sealed chamber extending between said electrolyte and said cathode for wetting the cathode with the electrolyte and for establishing electrical contact between the electrolyte and the cathode.
Claim 2
Dependent Claim
138 words
In an apparatus for use in analysing the concentration of nitrogen oxides in a gas; said apparatus including means for converting nitrogen oxides in the gas to be analysed into nitrogen dioxide and an electrolytic cell for producing an electrical signal proportional to the concentration of the nitrogen dioxide in the converted gas; the improvement comprising an electrolytic cell containing a neutral aqueous electrolyte in a sealed chamber; an anode in said sealed chamber comprising activated carbon within a perforated jacket immersed in said electrolyte; a cathode in said sealed chamber comprising a platinum element supported above the electrolyte for direct contact with the converted gas; and capillary means in said sealed chamber extending between said electrolyte and said cathode for wetting the cathode with the electrolyte and for establishing electrical contact between the electrolyte and the cathode.
Claim 3
Dependent Claim
25 words
Apparatus according to claim 1 and further comprising means for causing the gas to flow in succession through the converting means and the electrolytic cell.
Claim 4
Dependent Claim
22 words
Apparatus according to claim 2, wherein the means for causing the gas to flow is in the form of a battery-powered fan.
Claim 5
Dependent Claim
31 words
Apparatus according to claim 1, wherein the cathode is in the form of platinum tape wound in helical fashion around a tubular support, the platinum tape being arranged above the jacket.
Claim 6
Dependent Claim
36 words
Apparatus according to claim 4, wherein the support at least extends into the perforated jacket and platinum wire is wound in helical fashion around the support inside the jacket to establish connection with the anodic carbon.
Claim 7
Dependent Claim
19 words
Apparatus according to claim 4, wherein said wetting-means comprises a sheath of glass fibres partly surrounding the tubular support.
Claim 8
Dependent Claim
38 words
Apparatus according to claim 1, wherein a cylindrical housing with a cap defines the sealed chamber and a pair of terminals are provided on the cap and are connected with the anode and cathode, respectively, with platinum wire.
Claim 9
Dependent Claim
34 words
Apparatus according to claim 1 wherein the converting means comprises an oxidizing agent contained in another sealed chamber provided with an ingress and egress for the gas which is converted in said other chamber.
Claim 10
Dependent Claim
16 words
Apparatus according to claim 1 and further comprising means for drying the gas prior to conversion.
Claim 11
Dependent Claim
19 words
Apparatus according to claim 9, wherein the drying means comprises a dehydrating agent contained in a further sealed chamber.
Claim 12
Dependent Claim
22 words
Apparatus according to claim 1, wherein the sealed chamber is defined by a housing which is made from a transparent acrylic resin.
Claim 13
Dependent Claim
19 words
Apparatus according to claim 1, and further comprising a flow meter for indicating the flow rate of the gas.
Claim 14
Dependent Claim
44 words
Apparatus according to claim 1 and further comprising a measuring circuit with means for indicating or recording the electrical signal produced by the electrolytic cell and calibrating means for backing-off the e.m.f. produced by the cell when pure air is supplied to the cell.
References Cited (Backward Citations)
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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) | 1983-04-08 | 1983-10-08 | 1984-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-08 | 1987-10-08 | 1988-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-08 | 1991-10-08 | 1992-04-08 | $7700.00 | Window Closed / Lapsed |