Patent US5076904A successfully refreshed from Google Patents.
US5076904A
Expired / Lapsed
US
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Electrochemical measuring cell for determining ammonia or hydrazine in a measuring sample
Assignee: Draegerwerk AG and Co KGaA
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Filing: 1990-04-12
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Granted: 1991-12-31
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Expires: 2010-04-12
Abstract
Abstract The invention is directed to an electrochemical measuring cell for determining ammonia or hydrazine in a gaseous or liquid measuring sample. The measuring cell has at least one measuring electrode and at least one counter electrode which are disposed in an electrolyte chamber filled with a soluble electrolyte. The electrolyte chamber is closed off in the direction facing toward the measuring sample by a permeable membrane. The measuring cell provides a selective ammonia measurement having the following advantages: a short response time, a linear response and a low tendency to drift. The electrodes of the measuring cell are so configured that the oxidation of the ammonia as a measurement reaction has no influence on the sensitivity of the measuring cell. For this purpose, at least the measuring electrode is provided with a coating containing cobalt oxide which is in direct contact with the electrolyte.
Inventors
- 👤 Herbert Kiesele
- 👤 Uwe Kuhn
- 👤 Stephan Haupt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:26
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/4045
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
121 words
An electrochemical measuring cell for determining ammonia or hydrazine in a fluid measuring sample, the measuring cell comprising: a housing having an opening directed toward the sample to be measured and defining an electrolyte chamber; a soluble electrolyte contained in said chamber; a permeable membrane mounted on said housing for closing off said chamber; a measuring electrode and a counter electrode disposed in said chamber so as to be in spaced relationship to each other; said measuring electrode having a coating containing cobalt oxide and said coating being formed on said measuring electrode so as to be in direct contact with said electrolyte; and, a reference electrode disposed in said electrolyte and having a coating formed thereon which contains cobalt oxide.
Claim 2
Dependent Claim
121 words
An electrochemical measuring cell for determining ammonia or hydrazine in a fluid measuring sample, the measuring cell comprising: a housing having an opening directed toward the sample to be measured and defining an electrolyte chamber; a soluble electrolyte contained in said chamber; a permeable membrane mounted on said housing for closing off said chamber; a measuring electrode and a counter electrode disposed in said chamber so as to be in spaced relationship to each other; said measuring electrode having a coating containing cobalt oxide and said coating being formed on said measuring electrode so as to be in direct contact with said electrolyte; and, a reference electrode disposed in said electrolyte and having a coating formed thereon which contains cobalt oxide.
Claim 3
Dependent Claim
32 words
The electrochemical measuring cell of claim 1, said measuring electrode and said reference electrode each including a carrier made of a noble metal and said coating being electrolytically deposited on said carrier.
Claim 4
Dependent Claim
36 words
The electrochemical measuring cell of claim 1, said measuring electrode and said reference electrode each including a carrier made of an alloy containing cobalt and said coating being an oxide layer formed by oxidizing said alloy.
Claim 5
Dependent Claim
124 words
An electrochemical measuring cell for determining ammonia or hydrazine in a fluid measuring sample, the measuring cell comprising: a housing having an opening directed toward the sample to be measured and defining an electrolyte chamber; a soluble electrolyte contained in said chamber; a permeable membrane mounted on said housing for closing off said chamber; a measuring electrode and a counter electrode disposed in said chamber so as to be in spaced relationship to each other; said measuring electrode having a coating containing cobalt oxide in direct contact with said electrolyte; said coating being formed on said measuring electrode by an electrolytic deposition on said measuring electrode; and, a reference electrode disposed inn said electrolyte and having a coating formed thereon which contains cobalt oxide.
Claim 6
Dependent Claim
124 words
An electrochemical measuring cell for determining ammonia or hydrazine in a fluid measuring sample, the measuring cell comprising: a housing having an opening directed toward the sample to be measured and defining an electrolyte chamber; a soluble electrolyte contained in said chamber; a permeable membrane mounted on said housing for closing off said chamber; a measuring electrode and a counter electrode disposed in said chamber so as to be in spaced relationship to each other; said measuring electrode having a coating containing cobalt oxide in direct contact with said electrolyte; said coating being formed on said measuring electrode by an electrolytic deposition on said measuring electrode; and, a reference electrode disposed inn said electrolyte and having a coating formed thereon which contains cobalt oxide.
Claim 7
Dependent Claim
27 words
The electrochemical measuring cell of claim 4, said measuring electrode including a carrier made of a noble metal and said coating being electrolytically deposited on said carrier.
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) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |