Patent US3977830A successfully refreshed from Google Patents.
US3977830A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silver nitrite reactant for measuring SO2
Assignee: ENVIRONMENTAL MONITORING & SERVICES Inc A CORP OF
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Filing: 1975-03-21
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Granted: 1976-08-31
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Expires: 1995-03-21
Abstract
Abstract Sulphur dioxide is reacted with silver nitrite at room temperature to release nitrogen dioxide in a known ratio and the nitrogen dioxide may, then, be measured as an indication of the presence and amount of sulphur dioxide.
Inventors
- 👤 Leo E. Topol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:27
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0027; G01N33/0036; G01N33/0042; G01N33/0011; G01N33/0013; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y10; Y10T; Y10T436/00; Y10T436/18; Y10T436/186
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
101 words
A sulphur dioxide measuring device comprising: a housing defining a gas passageway, a quantity of silver nitrite disposed in a gas-permeable form located in said gas passageway, nitrogen dioxide measuring means located downstream of said quantity of silver nitrite and in flow communication with said gas passageway, and means for passing a gas through said quantity of silver nitrite to allow any sulphur dioxide present in said gas to react with said silver nitrite to form nitrogen dioxide for passage to said nitrogen dioxide measuring means and thereby provide an indication of the concentration of sulphur dioxide contained in said gas.
Claim 2
Dependent Claim
101 words
A sulphur dioxide measuring device comprising: a housing defining a gas passageway, a quantity of silver nitrite disposed in a gas-permeable form located in said gas passageway, nitrogen dioxide measuring means located downstream of said quantity of silver nitrite and in flow communication with said gas passageway, and means for passing a gas through said quantity of silver nitrite to allow any sulphur dioxide present in said gas to react with said silver nitrite to form nitrogen dioxide for passage to said nitrogen dioxide measuring means and thereby provide an indication of the concentration of sulphur dioxide contained in said gas.
Claim 3
Dependent Claim
17 words
The device of claim 1 wherein: said quantity of silver nitrite is a self-supporting, yet porous, capsule.
Claim 4
Dependent Claim
14 words
The device of claim 2 wherein: said capsule is formed of compacted silver nitrite.
Claim 5
Dependent Claim
15 words
The device of claim 1 wherein said nitrogen dioxide measuring means is an electrochemical detector.
Claim 6
Dependent Claim
15 words
The device of claim 1 wherein said nitrogen dioxide measuring means is a colorimetric detector.
Claim 7
Dependent Claim
15 words
The device of claim 1 wherein said nitrogen dioxide measuring means is a conductimetric detector.
Claim 8
Dependent Claim
15 words
The device of claim 1 wherein said nitrogen dioxide measuring means is a chemiluminescent detector.
Claim 9
Independent Claim
81 words
An apparatus for adapting a detector of nitrogen dioxide to measure sulphur dioxide, said apparatus comprising: a housing defining a gas passageway, a quantity of silver nitrite disposed in a gas-permeable form located in said gas passageway, means for passing a gas through said quantity of silver nitrite to allow any sulphur dioxide present in said gas to react with the silver nitrite to form nitrogen dioxide, and means for delivering the nitrogen dioxide resulting from said reaction to said detector.
Claim 10
Independent Claim
81 words
An apparatus for adapting a detector of nitrogen dioxide to measure sulphur dioxide, said apparatus comprising: a housing defining a gas passageway, a quantity of silver nitrite disposed in a gas-permeable form located in said gas passageway, means for passing a gas through said quantity of silver nitrite to allow any sulphur dioxide present in said gas to react with the silver nitrite to form nitrogen dioxide, and means for delivering the nitrogen dioxide resulting from said reaction to said detector.
Claim 11
Independent Claim
70 words
A method of measuring the amount of sulphur dioxide contained in a gas, said method comprising the steps of: passing said gas through a quantity of silver nitrite to allow any sulphur dioxide contained in said gas to react with said silver nitrite to form nitrogen dioxide, and measuring the nitrogen dioxide resulting from said reaction as an indication of the presence and amount of sulphur dioxide in said gas.
Claim 12
Independent Claim
70 words
A method of measuring the amount of sulphur dioxide contained in a gas, said method comprising the steps of: passing said gas through a quantity of silver nitrite to allow any sulphur dioxide contained in said gas to react with said silver nitrite to form nitrogen dioxide, and measuring the nitrogen dioxide resulting from said reaction as an indication of the presence and amount of sulphur dioxide in said gas.
Claim 13
Dependent Claim
21 words
The method of claim 9 wherein: the reaction of sulphur dioxide with said silver nitrite is carried out at ambient temperatures.
Claim 14
Dependent Claim
29 words
The method of claim 9 wherein: the reaction of sulphur dioxide with said silver nitrite is carried out at a relative humidity in the range of about 30-80 percent.
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) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |