US4397888A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thick film sensor for hydrogen and carbon monoxide
Assignee: Rosemount Inc
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Filing: 1982-03-10
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Granted: 1983-08-09
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Expires: 2002-03-10
Abstract
Abstract An improved thick film stannic oxide sensor is disclosed whereby the sensitivity of the sensor to CO is enhanced by the addition of a rare earth oxide to the sensor composition and the catalytic reactivity of the sensor, when contacted by a gas containing a reducing constituent, i.e., H 2 or CO, and oxygen, is enhanced by employing RuCl 3 or PtCl 2 as a catalyst.
Inventors
- 👤 Lymperios N. Yannopoulos
- 👤 Chikara Hirayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:00
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
120 words
A method of preparing a stannic oxide gas detecting film device responsive primarily to H 2 present in an oxygen containing gas environment, comprising the steps of, solution precipitation of Sn(SO 4 ) 2 and SnO 2 , thermally decomposing the Sn(SO 4 ) 2 to SnO 2 , adding the SnO 2 to a catalyst solution of acetone or ethanol, adding a sintering agent to the catalyst solution containing SnO 2 and stirring, filtering the resulting catalyst dopeed oxide mixture, drying the filtered mixture to produce a dry powder, mixing the resulting dry powder with β-terpineol to form a paste, applying the paste to a non-conductive substrate, and drying the paste to form a stannic oxide gas detecting film.
Claim 2
Independent Claim
120 words
A method of preparing a stannic oxide gas detecting film device responsive primarily to H 2 present in an oxygen containing gas environment, comprising the steps of, solution precipitation of Sn(SO 4 ) 2 and SnO 2 , thermally decomposing the Sn(SO 4 ) 2 to SnO 2 , adding the SnO 2 to a catalyst solution of acetone or ethanol, adding a sintering agent to the catalyst solution containing SnO 2 and stirring, filtering the resulting catalyst dopeed oxide mixture, drying the filtered mixture to produce a dry powder, mixing the resulting dry powder with β-terpineol to form a paste, applying the paste to a non-conductive substrate, and drying the paste to form a stannic oxide gas detecting film.
Claim 3
Dependent Claim
49 words
A method as claimed in claim 1 wherein said step of thermally decomposing occurs at about 400° C., said step of drying the filtered mixture occurs at about 700° C. in about one hour, and said step of drying the paste occurs at about 400° in about one hour.
Claim 4
Independent Claim
148 words
A method of preparing a stannic oxide gas detecting film device responsive primarily to CO present in an oxygen containing gas environment, comprising the steps of, solution precipitation of Sn(SO 4 ) 2 and SnO 2 , thermally decomposing the Sn(SO 4 ) 2 to SnO 2 , adding the SnO 2 to a catalyst solution of acetone or ethanol, adding a sintering agent to the catalyst solution containing SnO 2 and stirring, filtering the resulting catalyst doped oxide mixture, drying the filtered mixture to produce a dry powder, adding La 2 O 3 to the dried powder, sintering the mixture of the La 2 O 3 and the dry powder; mixing the sintered mixture of La 2 O 3 and dry powder with β-terpineol to form a paste, applying the paste to a non-conductive substrate, and drying the paste to form a stannic oxide gas detecting film.
Claim 5
Independent Claim
148 words
A method of preparing a stannic oxide gas detecting film device responsive primarily to CO present in an oxygen containing gas environment, comprising the steps of, solution precipitation of Sn(SO 4 ) 2 and SnO 2 , thermally decomposing the Sn(SO 4 ) 2 to SnO 2 , adding the SnO 2 to a catalyst solution of acetone or ethanol, adding a sintering agent to the catalyst solution containing SnO 2 and stirring, filtering the resulting catalyst doped oxide mixture, drying the filtered mixture to produce a dry powder, adding La 2 O 3 to the dried powder, sintering the mixture of the La 2 O 3 and the dry powder; mixing the sintered mixture of La 2 O 3 and dry powder with β-terpineol to form a paste, applying the paste to a non-conductive substrate, and drying the paste to form a stannic oxide gas detecting film.
Claim 6
Dependent Claim
50 words
A method as claimed in claim 3 wherein said step of thermally decomposing occurs at about 400° C., said step of drying the filtered mixture occurs at about 700° C. in about one hour, and said step of drying the paste occurs at about 400° C. in about one hour.
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) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |