US4595486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochemical gas sensor
Assignee: ENVIROMENTAL TECHNOLOGIES GROUP Inc
•
Filing: 1985-02-01
•
Granted: 1986-06-17
•
Expires: 2005-02-01
Abstract
Abstract An electrochemical gas sensor is described for detecting a gas constituent, for example hydrazine in a gas ambient incorporating an electrochemical cell including a reference electrode, counter electrode and sensing electrode spaced apart and with an electrolyte in contact with each electrode and comprising n-methyl-2-pyrrolidone and a salt soluble therein, for example tetraalkyl ammonium salt. The invention overcomes the problem of specificity, service life and operating temperature range associated with aqueous electrochemical gas sensors.
Inventors
- 👤 John C. Schmidt
- 👤 Donald N. Campbell
- 👤 Sandra B. Clay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:37
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/4045
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
86 words
An electrochemical gas sensor comprising: a reference electrode, a counter electrode and a sensing electrode spaced apart from each other, an electrolyte in the spaces between said electrodes in contact with each said electrodes, said electrolyte including n-methyl-2-pyrrolidone and a salt soluble therein, circuit means for maintaining a predetermined voltage on said sensing electrode with respect to said reference electrode, and means responsive to electric current from said sensing electrode to provide an indication of the concentration of a gas in an ambient to be monitored.
Claim 2
Dependent Claim
86 words
An electrochemical gas sensor comprising: a reference electrode, a counter electrode and a sensing electrode spaced apart from each other, an electrolyte in the spaces between said electrodes in contact with each said electrodes, said electrolyte including n-methyl-2-pyrrolidone and a salt soluble therein, circuit means for maintaining a predetermined voltage on said sensing electrode with respect to said reference electrode, and means responsive to electric current from said sensing electrode to provide an indication of the concentration of a gas in an ambient to be monitored.
Claim 3
Dependent Claim
17 words
The electrochemical gas sensor of claim 1 wherein said reference and sensing electrode includes a noble metal.
Claim 4
Dependent Claim
13 words
The electrochemical gas sensor of claim 1 wherein said sensing electrode includes platinum.
Claim 5
Dependent Claim
13 words
The electrochemical gas sensor of claim 1 wherein said sensing electrode includes iridium.
Claim 6
Dependent Claim
13 words
The electrochemical gas sensor of claim 1 wherein said sensing electrode includes rhodium.
Claim 7
Dependent Claim
25 words
The electrochemical gas sensor of claim 1 wherein the concentration of said salt soluble therein is in the range from 0.005 to 2 molar solution.
Claim 8
Dependent Claim
16 words
The electrochemical gas sensor of claim 1 wherein said salt soluble therein includes tetraalkyl ammonium salt.
Claim 9
Dependent Claim
25 words
The electrochemical gas sensor of claim 7 wherein the concentration of said tetraalkyl ammonium salt is in the range from 0.005 to 2 molar solution.
Claim 10
Dependent Claim
15 words
The electrochemical gas sensor of claim 7 wherein said tetraalkyl ammonium salt includes tetraethylammonium tetrafluoroborate.
Claim 11
Dependent Claim
20 words
The electrochemical gas sensor of claim 1 wherein said electrolyte includes a 0.2 molar solution of tetraethylammonium tetrafluoroborate in n-methyl-2-pyrrolidone.
Claim 12
Dependent Claim
42 words
The electrochemical gas sensor of claim 1 wherein said circuit means maintains said predetermined voltage at -100 millivolts ±5 millivolts on said sensing electrode with respect to said reference electrode for detecting hydrazine, monomethyl hydrazine or unsymmetrical dimethyl hydrazine in said ambient.
Claim 13
Dependent Claim
15 words
The electrochemical gas sensor of claim 1 wherein said salt soluble therein includes lithium perchlorate.
Claim 14
Dependent Claim
43 words
An electrochemical cell comprising: a reference electrode, a counter electrode and a sensing electrode spaced apart from each other, and an electrolyte in the spaces between said electrodes in contact with each said electrodes, said electrolyte including n-methyl-2-pyrrolidone and a tetraalkyl ammonium salt.
Claim 15
Dependent Claim
43 words
An electrochemical cell comprising: a reference electrode, a counter electrode and a sensing electrode spaced apart from each other, and an electrolyte in the spaces between said electrodes in contact with each said electrodes, said electrolyte including n-methyl-2-pyrrolidone and a tetraalkyl ammonium salt.
Claim 16
Dependent Claim
16 words
The electrochemical cell of claim 13 wherein said reference and sensing electrode includes a noble metal.
Claim 17
Dependent Claim
12 words
The electrochemical cell of claim 13 wherein said sensing electrode includes platinum.
Claim 18
Dependent Claim
12 words
The electrochemical cell of claim 13 wherein said sensing electrode includes iridium.
Claim 19
Dependent Claim
12 words
The electrochemical cell of claim 13 wherein said sensing electrode includes rhodium.
Claim 20
Dependent Claim
24 words
The electrochemical cell of claim 13 wherein the concentration of said tetraalkyl ammonium salt is in the range from 0.005 to 2 molar solution.
Claim 21
Dependent Claim
14 words
The electrochemical cell of claim 1 wherein said tetraalkyl ammonium salt includes tetraethylammonium tetrafluoroborate.
Claim 22
Dependent Claim
17 words
The electrochemical cell of claim 19 wherein said electrolyte includes a 0.2 molar solution of tetraethylammonium tetrafluoroborate.
Claim 23
Dependent Claim
41 words
An electrochemical cell comprising: a reference electrode, a counter electrode and a sensing electrode spaced apart from each other, and an electrolyte in the spaces between said electrodes in contact with each said electrodes, said electrolyte including n-methyl-2-pyrrolidone and lithium perchlorate.
Claim 24
Dependent Claim
41 words
An electrochemical cell comprising: a reference electrode, a counter electrode and a sensing electrode spaced apart from each other, and an electrolyte in the spaces between said electrodes in contact with each said electrodes, said electrolyte including n-methyl-2-pyrrolidone and lithium perchlorate.
References Cited (Backward Citations)
US3776832A
Cited
US3966579A
Cited
US4201634A
Cited
US4169779A
Cited
US4184937A
Cited
US4268370A
Cited
US4406770A
Cited
US4525266A
Cited
US4525704A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |