Patent US3725702A successfully refreshed from Google Patents.
US3725702A
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Infrared gas analyzer
Assignee: ABB Training Center GmbH and Co KG
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Filing: 1969-01-29
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Granted: 1973-04-03
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Expires: 1989-01-29
Abstract
Abstract Detector for analyzer is made up of four gas chambers, an incident pair and a respectively alined pair directly after the incident pair, chambers of the pairs being cross-connected by gas conduits. Detector measures difference in the sums of energy absorbed in cross-connected pairs, when analysis and comparison beams are respectively directed into the alined pairs, giving null readings for null values and with great stability of null point.
Inventors
- 👤 W Schaefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:30
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/37
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
259 words
In an infrared gas analyzer having means for providing analysis and comparison beams, a cuvette in the path of the analysis beam for holding an analysis sample to be analyzed for an absorptive gas, the improvement comprising: a detector for comparing the intensity of radiation passing through the cuvette with that of the comparison beam the detector including first incident and immediately following chambers, said first chambers being substantially aligned with one of the beams, said detector further including second incident and immediately following chambers, said second chambers being both substantially aligned with the other beam, the first and second chambers containing said absorptive gas; first connecting duct means for connecting the first incident chamber to the second following chamber for equalizing gas pressure therein; second connecting duct means for connecting the second incident chamber to the first following chamber for equalizing gas pressure therein, the first and second incident chambers, respectively, being substantially isolated from the first and second following chambers, respectively, with respect to gas movement therebetween, the following chambers being longer than the incident chambers in direction of beam propagation; and meanS for measuring the difference between two sums of energy, one sum being that of energy absorbed by the gas in the incident chamber in one beam plus that absorbed by he gas in the following chamber in the other beam, and the other sum being that of energy absorbed by the gas in the incident chamber in said other beam plus that absorbed by the gas in the following chamber in said one beam.
Claim 2
Dependent Claim
259 words
In an infrared gas analyzer having means for providing analysis and comparison beams, a cuvette in the path of the analysis beam for holding an analysis sample to be analyzed for an absorptive gas, the improvement comprising: a detector for comparing the intensity of radiation passing through the cuvette with that of the comparison beam the detector including first incident and immediately following chambers, said first chambers being substantially aligned with one of the beams, said detector further including second incident and immediately following chambers, said second chambers being both substantially aligned with the other beam, the first and second chambers containing said absorptive gas; first connecting duct means for connecting the first incident chamber to the second following chamber for equalizing gas pressure therein; second connecting duct means for connecting the second incident chamber to the first following chamber for equalizing gas pressure therein, the first and second incident chambers, respectively, being substantially isolated from the first and second following chambers, respectively, with respect to gas movement therebetween, the following chambers being longer than the incident chambers in direction of beam propagation; and meanS for measuring the difference between two sums of energy, one sum being that of energy absorbed by the gas in the incident chamber in one beam plus that absorbed by he gas in the following chamber in the other beam, and the other sum being that of energy absorbed by the gas in the incident chamber in said other beam plus that absorbed by the gas in the following chamber in said one beam.
Claim 3
Dependent Claim
33 words
In an infrared analyzer as claimed in claim 1 said means for measuring being a differential pressure measurer connected between said first and second following chambers for measuring difference in gas pressure therebetween.
Claim 4
Dependent Claim
26 words
In an analyzer as claimed in claim 2, and means for equal phase modulation of both beams, and said differential pressure measurer being a membrane condenser.
Claim 5
Dependent Claim
23 words
In an analyzer as claimed in claim 2, wherein one radiator is provided for each beam as the means for producing the beams.
Claim 6
Dependent Claim
25 words
In an analyzer as claimed in claim 2, the two incident chambers being of identical geometry and the two following chambers being of identical geometry.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |