US4355056A
Expired / Lapsed
US
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Method of manufacturing a combustibles sensor
Assignee: Elsag International BV
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Filing: 1981-03-31
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Granted: 1982-10-19
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Expires: 2001-03-31
Abstract
Abstract A method of manufacturing a differential thermocouple combustibles sensor is disclosed which makes the sensor relatively insensitive to sulfur poisoning. To accomplish this the catalytic thermocouple junction of a catalytic-non-catalytic junction pair is formed by coating it with a gel to increase the surface area and then with a chloroplatinic acid solution to make it catalytic. The catalytic junction is then treated with H 2 S to achieve a high catalyst surface area.
Inventors
- 👤 Ralph A. Dalla Betta
- 👤 Sharon L. Zimmerlin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:50
CPC Classifications
G; G01; G01N; G01N25/00; G01N25/20; G01N25/22; G01N25/28; G01N25/30; G01N25/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
86 words
A method of manufacturing a combustibles sensor which is relatively insensitive to sulfur poisoning comprising the steps of: providing a first temperature measurement device which has a temperature varying electrical property; coating said temperature measurement device with a gel to form a high surface area substrate with increased surface area over said temperature measurement device; coating said gel high surface area substrate with a catalytic material; and treating said catalytic material coating with H 2 S to achieve a high surface area of the catalytic material.
Claim 2
Independent Claim
86 words
A method of manufacturing a combustibles sensor which is relatively insensitive to sulfur poisoning comprising the steps of: providing a first temperature measurement device which has a temperature varying electrical property; coating said temperature measurement device with a gel to form a high surface area substrate with increased surface area over said temperature measurement device; coating said gel high surface area substrate with a catalytic material; and treating said catalytic material coating with H 2 S to achieve a high surface area of the catalytic material.
Claim 3
Dependent Claim
60 words
The method of claim 1 including the further steps of: providing a second temperature measurement device which has a temperature varying electrical property; connecting said first temperature measurement device to said second temperature measurement device to form a differential temperature measurement device; and coating said second temperature measurement device with a low surface area cement to form a non-catalytic surface.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein said gel is a mixture of γ-alumina and a binding agent consisting of a colloidal suspension of the γ-alumina.
Claim 5
Dependent Claim
24 words
The method of claim 1 wherein said coating of said high surface area substrate is done with a solution of chloroplatinic acid and water.
Claim 6
Dependent Claim
27 words
The method of claim 4 wherein said treating of said catalytic material with H 2 S is continued until the catalytic coating turns from yellow to black.
Claim 7
Dependent Claim
55 words
The method of claim 5 further including after said treating said catalytic material the steps of: drying said treated catalytic material at approximately 100° C. for approximately 20 min; and heating said dryed catalytic material in approximately 500° C. air for approximately 1 hr to oxidize any free sulfur or metal sulfides in the device.
Claim 8
Dependent Claim
51 words
The method of claim 2 further including after said step of coating said second temperature measurement device the further steps of: drying said differential temperature measurement device at approximately 100° C. for approximately 20 min; and heating said differential temperature measurement device in approximately 500° C. air for approximately 1 hr.
Claim 9
Dependent Claim
28 words
The method of claim 2 wherein said coating of said second temperature measurement device is done with Alundum cement having a particle size of 50 μm or smaller.
Claim 10
Dependent Claim
15 words
The method of claim 1 wherein said first temperature measurement device is a Chromel-Alumel thermocouple.
Claim 11
Dependent Claim
16 words
The method of claim 2 wherein said first and second temperature measurement devices are Chromel-Alumel thermocouples.
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) | 1985-10-18 | 1986-04-19 | 1986-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-18 | 1990-04-19 | 1990-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-18 | 1994-04-19 | 1994-10-19 | $7700.00 | Window Closed / Lapsed |