US4281248A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nondispersive infrared gas analyzer
Assignee: ABB Training Center GmbH and Co KG
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Filing: 1980-04-30
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Granted: 1981-07-28
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Expires: 2000-04-30
Abstract
Abstract The cross-sensitivity of a two-beam infrared gas analyzer is reduced by using two differently long cells for the sample gas in the two beam paths. The path with the short sample gas cell is intercepted by a detector cell having highly absorbing wall while the detector cell in the other path is highly reflective, e.g., made of gold. The two detector cells are interconnected by a differential pressure chamber with capacitive pickup.
Inventors
- 👤 Walter Fabinski
- 👤 Udo Deptolla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:07
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/37; G01N21/59; G01N21/61
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
159 words
A nondispersive infrared gas analyzer having a source for infrared radiation as well as means for defining a first and a second path as well as chopper means for periodically interrupting radiation in each of said paths, further including first and second detection cells filled with gas of the type to be detected in the sample gas, the cells being respectively disposed in said first and second paths, there being additionally differential pressure sensing means with capacitive pickup connected to the first and second detection cells for responding to pressure differences in those detection cells and providing an electrical signal representative thereof, the improvement comprising: a first and a second cell for sample gas, respectively disposed in the first and the second path, the first cell being significantly shorter in the direction of the first path than the second cell; and the walls of the first detection cell absorbing more radiation than the walls of the second detection cells.
Claim 2
Dependent Claim
159 words
A nondispersive infrared gas analyzer having a source for infrared radiation as well as means for defining a first and a second path as well as chopper means for periodically interrupting radiation in each of said paths, further including first and second detection cells filled with gas of the type to be detected in the sample gas, the cells being respectively disposed in said first and second paths, there being additionally differential pressure sensing means with capacitive pickup connected to the first and second detection cells for responding to pressure differences in those detection cells and providing an electrical signal representative thereof, the improvement comprising: a first and a second cell for sample gas, respectively disposed in the first and the second path, the first cell being significantly shorter in the direction of the first path than the second cell; and the walls of the first detection cell absorbing more radiation than the walls of the second detection cells.
Claim 3
Dependent Claim
24 words
An analyzer as in claim 1, the walls of the first detection cell being black, the walls of the second detection cell being reflective.
Claim 4
Dependent Claim
19 words
An analyzer as in claim 1 or 2, the walls of the second detection cell being made of gold.
Claim 5
Dependent Claim
20 words
An analyzer as in claim 1 or 2, the first cell including additional absorbing means having a low heat capacity.
Claim 6
Dependent Claim
14 words
An analyzer as in claim 4, the additional means being a blackened wire mesh.
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) | 1984-07-27 | 1985-01-26 | 1985-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-27 | 1989-01-26 | 1989-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-27 | 1993-01-26 | 1993-07-28 | $7700.00 | Window Closed / Lapsed |