US4771176A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for quantitative analysis of hydrocarbon
Assignee: AVL List GmbH
•
Filing: 1986-12-03
•
Granted: 1988-09-13
•
Expires: 2006-12-03
Abstract
Abstract In conventional methods of quantitative hydrocarbon analysis in gaseous sles by means of infrared transmission, systematic inaccuracies may be found which are caused by changes in the composition of the components contained in the sample. Such inaccuracies typically amount to 10 to 30% of the measured value, with occasional rises of up to 100%. In order to eliminate this disadvantage the invention proposes that for determining the total mass of gaseous and condensed hydrocarbons radiation be used with a frequency band whose integral infrared absorption has approximately the same value for each of the main hydrocarbons present.
Inventors
- 👤 Erich J. Schiefer
- 👤 Wolfgang Schindler
- 👤 Peter W. Krempl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:46
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/3504
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
211 words
A method for determining the total mass of gaseous and condensed hydrocarbons in a gaseous sample which contains gaseous hydrocarbons, condensed hydrocarbons and carbon particles, said method comprising the steps of (1) passing electromagnetic radiation having a frequency band whose central wavelength is 3,465±0.05 μm, whose half-band width is 0.07 to 0.18 μm, whose 5% cuton is at a wavelength>3.35 μm and whose 5% cutoff is at a wavelength of<3.58 μm through said gaseous sample and through a reference volume, (2) measuring the intensity values of the electromagnetic radiation after passing through said gaseous sample and said reference volume in step (1), (3) determining the difference in intensity values measured in step (2) to provide a preliminary value of the total mass of gaseous and condensed hydrocarbons. (4) passing electromagnetic radiation having a wavelength of 3.8 to 4.15 μm through said gaseous sample and said reference volume, (5) measuring the intensity of the elelctromagnetic radiation after passing through said gaseous sample and said reference volume in step (4), (6) determining the difference in intensity values determined in step (B 5) to provide a value of the total mass of carbon particles in said gaseous sample, and (7) correcting the value obtained in step (3) with the value obtained in step (6).
Claim 2
Independent Claim
211 words
A method for determining the total mass of gaseous and condensed hydrocarbons in a gaseous sample which contains gaseous hydrocarbons, condensed hydrocarbons and carbon particles, said method comprising the steps of (1) passing electromagnetic radiation having a frequency band whose central wavelength is 3,465±0.05 μm, whose half-band width is 0.07 to 0.18 μm, whose 5% cuton is at a wavelength>3.35 μm and whose 5% cutoff is at a wavelength of<3.58 μm through said gaseous sample and through a reference volume, (2) measuring the intensity values of the electromagnetic radiation after passing through said gaseous sample and said reference volume in step (1), (3) determining the difference in intensity values measured in step (2) to provide a preliminary value of the total mass of gaseous and condensed hydrocarbons. (4) passing electromagnetic radiation having a wavelength of 3.8 to 4.15 μm through said gaseous sample and said reference volume, (5) measuring the intensity of the elelctromagnetic radiation after passing through said gaseous sample and said reference volume in step (4), (6) determining the difference in intensity values determined in step (B 5) to provide a value of the total mass of carbon particles in said gaseous sample, and (7) correcting the value obtained in step (3) with the value obtained in step (6).
Claim 3
Dependent Claim
109 words
A method according to claim 1, comprising the additional steps of (1) passing electromagnetic radiation having a frequency band whose wavelength is 3,365±0.025 μm, whose half-band width is<0.1 μm, whose 5% cuton is at a wavelength >3.29 μm and whose 5% cutoff is at a wavelength<3.45 μm through said gaseous sample and through said reference volume, (9) measuring the intensity values of the electromagnetic radiation after passing through said gaseous sample and said reference volume in step (8), (10) determining the difference in intensity values determined in step (9), and (11) computing a value of the total mass of gaseous hydrocarbons with values obtained in steps (7) and (10).
Claim 4
Dependent Claim
19 words
A method according to claim 2, wherein said electromagnetic radiations in steps (1) and (8) are provided by lasers.
Claim 5
Dependent Claim
42 words
A method according to claim 2, wherein said electromagnetic radiation in step (1) is provided by passing broad-band electromagnetic radiation through an interference filter whose transmission in a wavelength interval between 3.38 and 3.55 μm will exceed 50% of the maximum transmission.
Claim 6
Dependent Claim
42 words
A method according to claim 2, wherein said electromagnetic radiation in step (8) is provided by passing broad-band electromagnetic radiation through an interference filter whose transmission in a wavelength interval between 3.31 and 3.42 μm will exceed 50% of the maximum transmission.
Claim 7
Dependent Claim
42 words
A method according to claim 1, wherein said electromagnetic radiation in step (1) is provided by passing broad-band electromagnetic radiation through an interference filter whose transmission in a wavelength interval between 3.38 and 3.55 μm will exceed 50% of the maximum transmission.
Claim 8
Independent Claim
48 words
A method according to any of claims 3 to 5, wherein the transmission of said interference filters outside their pass-band in a wavelength range from 10 μm up to the visual range is less than 0.1% of the maximum transmission in the range of said respective central wavelength.
References Cited (Backward Citations)
US3932754A
Cited
CA1000070A
Cited
US3998557A
Cited
US3957372A
Cited
DE2557508A1
Cited
US4044257A
Cited
US4268751A
Cited
AT376301B
Cited
US4525627A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |