US4078981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
CO2 interference free O2 electrode
Assignee: Rosemount Inc
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Filing: 1976-12-03
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Granted: 1978-03-14
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Expires: 1996-12-03
Abstract
Abstract An improved electrode for use in oxygen determination is disclosed. Interference from carbon dioxide is eliminated by combining an improved electrolyte with means for permitting rapid electrolyte movement into and out of the space between the cathode and the membrane covering the cathode to maintain the pH of the electrolyte in the space substantially constant. The electrolyte consists of a KCl solution containing KOH of from 0.1 to 2%.
Inventors
- 👤 Radhakrishna M. Neti
- 👤 Ray L. Roggenkamp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:55
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
115 words
An improved polarographic oxygen electrode comprising: (a) a body having an enclosure therein and an opening into said enclosure; (b) a noble metal anode disposed within said enclosure; (c) a porous membrane disposed across said opening; (d) an electrolyte disposed within said enclosure, said electrolyte being a solution containing KCl at less than saturation and KOH at between 0.1 and 2.0 percent; (e) a gold cathode assembly disposed within said enclosure adjacent said membrane and including means for said electrolyte to interchange between a portion of said electrolyte disposed between said cathode and said membrane and the remainder of said electrolyte; and, (f) means for applying an electrical potential across said anode and said cathode.
Claim 2
Dependent Claim
115 words
An improved polarographic oxygen electrode comprising: (a) a body having an enclosure therein and an opening into said enclosure; (b) a noble metal anode disposed within said enclosure; (c) a porous membrane disposed across said opening; (d) an electrolyte disposed within said enclosure, said electrolyte being a solution containing KCl at less than saturation and KOH at between 0.1 and 2.0 percent; (e) a gold cathode assembly disposed within said enclosure adjacent said membrane and including means for said electrolyte to interchange between a portion of said electrolyte disposed between said cathode and said membrane and the remainder of said electrolyte; and, (f) means for applying an electrical potential across said anode and said cathode.
Claim 3
Dependent Claim
17 words
The improved electrode of claim 1 wherein: said gold cathode is spaced 0.003 inches from said membrane.
Claim 4
Dependent Claim
20 words
The improved electrode of claim 2 wherein: said electrolyte contains at least 5 percent KCl and contains 0.5 percent KOH.
Claim 5
Dependent Claim
22 words
The improved electrode of claim 1 wherein said electrolyte interchange means comprises: a wettable material disposed between said cathode and said membrane.
Claim 6
Dependent Claim
17 words
The improved electrode of claim 4 wherein: said wettable material is 0.003 inch thick glass fiber paper.
Claim 7
Dependent Claim
43 words
The improved electrode of claim 1 wherein: (a) said electrolyte interchange means is a porous cathode comprised of gold screen having gold powder pressed therein; and, (b) said anode is between 3 and 4 times larger in area as compared to said cathode.
Claim 8
Dependent Claim
19 words
The improved electrode of claim 6 wherein: said anode is comprised of gold screen having gold powder pressed therein.
Claim 9
Dependent Claim
25 words
The improved electrode of claim 7 wherein: (a) said gold screen is between 42 and 300 mesh; and, (b) said gold powder is 300 mesh.
Claim 10
Dependent Claim
96 words
An improved polarographic oxygen electrode of the type having a body with an enclosure therein and an opening into the enclosure, an anode in the enclosure, a porous membrane across the opening, a gold cathode within the enclosure adjacent the membrane, and a KCl electrolyte filling the enclosure, the improvement comprising: (a) means for the electrolyte to move into and out of the space between the gold cathode and the membrane whereby the electrolyte in said space is maintained at a substantially constant pH value; and, (b) the electrolyte containing between 0.1 and 2.0 percent KOH.
Claim 11
Dependent Claim
96 words
An improved polarographic oxygen electrode of the type having a body with an enclosure therein and an opening into the enclosure, an anode in the enclosure, a porous membrane across the opening, a gold cathode within the enclosure adjacent the membrane, and a KCl electrolyte filling the enclosure, the improvement comprising: (a) means for the electrolyte to move into and out of the space between the gold cathode and the membrane whereby the electrolyte in said space is maintained at a substantially constant pH value; and, (b) the electrolyte containing between 0.1 and 2.0 percent KOH.
Claim 12
Dependent Claim
31 words
The improved electrode of claim 9 wherein said means for electrolyte movement comprises: a glass fiber paper spacer between 0.002 and 0.010 inches thick disposed between the cathode and the membrane.
Claim 13
Dependent Claim
25 words
The improved electrode of claim 10 wherein: (a) said spacer is 0.003 inches thick; and, (b) said KOH is in the amount of 0.5 percent.
Claim 14
Dependent Claim
25 words
The improved electrode of claim 9 wherein: said means for electrolyte movement comprises pores disposed in the cathode whereby electrolyte can pass through the cathode.
Claim 15
Dependent Claim
19 words
The improved electrode of claim 12 wherein: the cathode is comprised of gold screen having gold powder pressed therein.
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) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |