US3721631A
Expired / Lapsed
US
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Humidity sensors comprising alkalimetal oxide,divanadium pentoxide and silicon
Assignee: SHINYEI KAISHA
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Filing: 1971-08-16
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Granted: 1973-03-20
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Expires: 1991-08-16
Abstract
Abstract A humidity sensor having a negative relative humidity coefficient of resistivity comprises 0.10 to 12.00 mole percent of alkali metal oxide, 0.05 to 10.00 mole percent of divanadium pentoxide and the balance substantially all silicon.
Inventors
- 👤 K Sumi
- 👤 O Asakura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:06
CPC Classifications
H; H01; H01B; H01B1/00; G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/121; Y; Y10; Y10S; Y10S252/00; Y10S252/963
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
17 words
The humidity sensor as set forth in claim 1 wherein said alkali metal oxide is sodium oxide.
Claim 2
Dependent Claim
25 words
The humidity sensor as set forth in claim 1 wherein said alkali metal oxide is contained in the amount of 0.20 to 10.00 mole percent.
Claim 3
Dependent Claim
24 words
The humidity sensor as set forth in claim 1 wherein said divanadium pentoxide is contained in the amount of 0.10 to 5.00 mole percent.
Claim 4
Dependent Claim
28 words
The humidity sensor as set forth in claim 1 wherein at least one of ZrO2 and SiO2 is substituted for 0.02 to 7.00 mole percent of said silicon.
Claim 5
Dependent Claim
22 words
The humidity sensor as set forth in claim 1 wherein Al2O3 is substituted for 0.01 to 5.00 mole percent of said silicon.
Claim 6
Dependent Claim
28 words
The humidity sensor as set forth in claim 1 wherein at least one of CaO and MgO is substituted for 0.01 to 2.00 mole percent of said silicon.
Claim 7
Independent Claim
70 words
A method of producing a humidity sensor having a negative relative humidity coefficient of resistivity, which comprises the steps of providing a compact of mixed powders consisting essentially of 0.10 to 12.00 mole percent of alkali metal oxide, 0.05 to 10.00 mole percent of divanadium pentoxide and the balance substantially all silicon, firing said compact at 500* C to 800* C and thereafter cooling the fired compact to room temperature.
Claim 8
Dependent Claim
16 words
The method as set forth in claim 8 wherein said alkali metal oxide is sodium oxide.
Claim 9
Dependent Claim
20 words
The method as set forth in claim 8 wherein said firing temperature is in the range of 600*C to 750*C.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |