US4709150A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting gas
Assignee: Gas Tech Inc
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Filing: 1986-03-18
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Granted: 1987-11-24
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Expires: 2006-03-18
Abstract
Abstract An analyzer to detect a specific gas in the atmosphere by infrared absorption, having a porous tube surrounding an enclosed column of air, the porous tube having an average pore size to permit gas to diffuse through it quickly, and having within the tube an infrared source, an infrared detector and an optical filter that passes those portions of the infrared spectrum most strongly absorbed by the gas, the analyzer having a time base generator to pulse the infrared source and electronic means to measure the maximum and minimum signals from the detector and a meter to indicate the difference between the maximum and minimum as a measure of the amount of the gas in the column of air.
Inventors
- 👤 Irvin G. Burough
- 👤 Robert O. Pellissier
- 👤 Kenneth W. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:36
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/3504; G01J; G01J5/00; G01J5/10; G01J5/12; G01N21/84; G01N21/85; G01N2021/8578; G01N2021/8585; G01N2201/00; G01N2201/06; G01N2201/069; G01N2201/0696
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
114 words
A cell for use in an analyzer for a gas comprising: a hollow, porous, support element exposed directly to ambient air and enclosing an elongated column of air at ambient pressure into which ambient air may diffuse, a source of radiant energy positioned within said porous element at one end of said column and sealed within said porous element, a detector for said radiant energy sealed within said porous element and positioned at the end of said column opposite said source and to receive radiation from said source, an optical filter positioned between said source and said detector, said optical filter passing only radiation from said source that is strongly absorbed by said gas.
Claim 2
Dependent Claim
114 words
A cell for use in an analyzer for a gas comprising: a hollow, porous, support element exposed directly to ambient air and enclosing an elongated column of air at ambient pressure into which ambient air may diffuse, a source of radiant energy positioned within said porous element at one end of said column and sealed within said porous element, a detector for said radiant energy sealed within said porous element and positioned at the end of said column opposite said source and to receive radiation from said source, an optical filter positioned between said source and said detector, said optical filter passing only radiation from said source that is strongly absorbed by said gas.
Claim 3
Dependent Claim
23 words
The cell of claim 1 wherein the average pore size of said porous element is from about 0.3 microns to about 100 microns.
Claim 4
Dependent Claim
12 words
The cell of claim 1 wherein said porous element is porous plastic.
Claim 5
Dependent Claim
12 words
The cell of claim 1 wherein said porous element is sintered metal.
Claim 6
Dependent Claim
12 words
The cell of claim 4 wherein said porous element is stainless steel.
Claim 7
Dependent Claim
12 words
The cell of claim 4 wherein said porous element is sintered bronze.
Claim 8
Dependent Claim
15 words
The cell of claim 1 wherein said source of radiant energy is a tungsten filament.
Claim 9
Dependent Claim
14 words
The cell of claim 1 wherein said source of radiant energy is a laser.
Claim 10
Dependent Claim
12 words
The cell of claim 1 wherein said detector is a thermovoltaic device.
Claim 11
Dependent Claim
173 words
An analyzer for a gas comprising: a hollow, porous, support element exposed directly to ambient air and enclosing an elongated column of air at ambient pressure into which ambient air may diffuse, a source of radiant energy positioned within said porous element at one end of said column and sealed within said porous element, a detector for said radiant energy sealed within said porous element and positioned at the end of said column opposite said source and to receive radiation from said source, an optical filter positioned between said source and said detector, said optical filter passing only radiation from said source that is strongly absorbed by said gas, means to pulse said source electronically at predetermined intervals, means pulsed at the same intervals to detect a minimum signal from said detector, means pulsed at the same intervals to detect a maximum signal from said detector, and means to indicate the differences between said minimum signal and said maximum signal, said means calibrated to indicate the quantity of said gas in said column.
Claim 12
Dependent Claim
173 words
An analyzer for a gas comprising: a hollow, porous, support element exposed directly to ambient air and enclosing an elongated column of air at ambient pressure into which ambient air may diffuse, a source of radiant energy positioned within said porous element at one end of said column and sealed within said porous element, a detector for said radiant energy sealed within said porous element and positioned at the end of said column opposite said source and to receive radiation from said source, an optical filter positioned between said source and said detector, said optical filter passing only radiation from said source that is strongly absorbed by said gas, means to pulse said source electronically at predetermined intervals, means pulsed at the same intervals to detect a minimum signal from said detector, means pulsed at the same intervals to detect a maximum signal from said detector, and means to indicate the differences between said minimum signal and said maximum signal, said means calibrated to indicate the quantity of said gas in said column.
Claim 13
Dependent Claim
32 words
The analyzer of claim 10 having a single means to pulse said source, to pulse said means to detect a minimum signal, and to pulse said means to detect a maximum signal.
Claim 14
Dependent Claim
23 words
The analyzer of claim 10 wherein the average pore size of said porous element is from about 0.3 microns to about 100 microns.
Claim 15
Dependent Claim
12 words
The analyzer of claim 10 wherein said porous element is sintered metal.
Claim 16
Dependent Claim
12 words
The analyzer of claim 13 wherein said porous element is stainless steel.
Claim 17
Dependent Claim
12 words
The analyzer of claim 13 wherein said porous element is sintered bronze.
Claim 18
Dependent Claim
12 words
The analyzer of claim 10 wherein said porous element is porous plastic.
Claim 19
Dependent Claim
15 words
The analyzer of claim 10 wherein said source of radiant energy is a tungsten filament.
Claim 20
Dependent Claim
14 words
The analyzer of claim 10 wherein said source of radiant energy is a laser.
Claim 21
Dependent Claim
12 words
The analyzer of claim 10 wherein said detector is a thermovoltaic detector.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-23 | 1991-05-25 | 1991-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-23 | 1995-05-25 | 1995-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-23 | 1999-05-25 | 1999-11-24 | $7700.00 | Window Closed / Lapsed |