US4816749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrocemical sensor
Assignee: Bayer Diagnostic and Electronic GmbH
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Filing: 1986-04-15
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Granted: 1989-03-28
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Expires: 2006-04-15
Abstract
Abstract The electrochemical sensor, which is designed more especially for monitoring the correct function of exhaust gas cleaning means in exhaust gas systems, has a solid electrolyte and a diffusion barrier of porous material and is arranged downstream from the exhaust gas cleaning means in the exhaust gas pipe. The sensor operates in a temperature range of -50° C. to 500° C., throughout which it functions substantially independently of temperature. Preferably nitrogen oxides are used as representative components for monitoring the efficacy of the exhaust gas cleaning means and a signal is produced when the signal from the sensor exceeds a given value.
Inventors
- 👤 Hermann Schmidtpott
- 👤 Ingeborg Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:43
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/406; G01N27/407; G01N27/4073; G01N27/4074
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
88 words
An electrochemical sensor for the detection of nitrogen oxides and disposable downstream of a catalyst in an exhaust pipe, the sensor comprising at least two electrodes including an operating electrode comprising a diffusion barrier integral therewith and consisting of a porous metal, a counter electrode and a solid electrolyte disposed between the operating and counter electrodes, wherein the electrolyte is a solid state electrolyte comprising spinel type or heteropolyacid compounds which are free from phase changes or decompositions within a temperature range of -50° C. to +500° C.
Claim 2
Dependent Claim
88 words
An electrochemical sensor for the detection of nitrogen oxides and disposable downstream of a catalyst in an exhaust pipe, the sensor comprising at least two electrodes including an operating electrode comprising a diffusion barrier integral therewith and consisting of a porous metal, a counter electrode and a solid electrolyte disposed between the operating and counter electrodes, wherein the electrolyte is a solid state electrolyte comprising spinel type or heteropolyacid compounds which are free from phase changes or decompositions within a temperature range of -50° C. to +500° C.
Claim 3
Dependent Claim
12 words
The sensor as claimed in claim 1, further comprising a reference electrode.
Claim 4
Dependent Claim
16 words
The sensor as claimed in claim 1, wherein the counter electrode serves as a reference electrode.
Claim 5
Dependent Claim
18 words
The sensor as claimed in claim 3, wherein the operating electrode and counter electrode consist of different materials.
Claim 6
Dependent Claim
18 words
The sensor as claimed in claim 1, wherein the operating and counter electrodes consist of the same material.
Claim 7
Dependent Claim
36 words
The sensor as claimed in claim 1, wherein the solid electrolyte consists of at least one compound which in a temperature range of -50° C. to +500° C. has a conductivity of at least 10-11 ohm/cm.
Claim 8
Dependent Claim
27 words
The sensor as claimed in claim 1, wherein the solid electrolyte consists of at least one compound having essentially inert behavior in relation to the electrode materials.
Claim 9
Dependent Claim
22 words
The sensor as claimed in claim 1, wherein the operating electrode consists of gold and the diffusion barrier consists of porous gold.
Claim 10
Dependent Claim
23 words
The sensor as claimed in claim 8, wherein the counter electrode consists of at least one platinum, palladium, rhodium, silver and ruthenium oxide.
Claim 11
Dependent Claim
23 words
The sensor as claimed in claim 8, wherein the counter electrode consists of silver and the reference electrode consists of AgNO 3 .
Claim 12
Dependent Claim
29 words
The sensor as claimed in claim 8, wherein the counter electrode, consists of a mixture from the group of Pd//PdO, Ni/NiO, Cu/Cu 2 O, Ag/AgC1 and Pd/PdH x .
Claim 13
Dependent Claim
25 words
The sensor as claimed in claim 11, wherein the oxide mixture has a sufficiently high conductivity to produce an output signal within the nano-ampere range.
Claim 14
Dependent Claim
50 words
The sensor as claimed in claim 1, wherein the diffusion barrier consists of porous material formed by a metal paste, which is provided with finely-divided material capable of evaporating at raised temperatures and which after application to a substrate is brought to a temperature at which the added material evaporates.
Claim 15
Dependent Claim
16 words
The sensor as claimed in claim 13, wherein the metal paste is applied by screen printing.
Claim 16
Dependent Claim
14 words
The sensor as claimed in claim 13, wherein the added material is a propellant.
Claim 17
Dependent Claim
13 words
The sensor as claimed in claim 13, wherein the added material is polystyrene.
Claim 18
Dependent Claim
12 words
The sensor as claimed in the diffusion barrier is formed by sputtering.
Claim 19
Dependent Claim
32 words
The sensor as claimed in claim 17, wherein the sensor consists of two essentially identical sensor elements, one element exposed to exhaust gases and the other element exposed to a reference gas.
Claim 20
Dependent Claim
14 words
The sensor as claimed in claim 18, wherein the reference gas is external air.
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) | 1992-03-27 | 1992-09-26 | 1993-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-27 | 1996-09-26 | 1997-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-27 | 2000-09-26 | 2001-03-28 | $7700.00 | Window Closed / Lapsed |