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Method for calibrating a spectrograph for gaseous samples

Assignee: Agilent Technologies Inc
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Filing: 1992-12-03
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Granted: 1994-08-23
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Expires: 2012-12-03
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Abstract

Abstract A method for field calibrating a system adapted for spectrographic analysis of gaseous substances. The method uses an easily available gas, for example ambient air, thereby providing for field calibration of the system without the inconvenience of using a purified noble gas and a pre-measured calibration gas mixture. During calibration, spectrograms from the easily available gas are generated by the system at various number density levels of the gas. Information from the spectrograms is then used in setting an operating parameter of the system.

Inventors

  • 👤 Richard J. Pittaro
  • 👤 Tad D. Simons

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 04:00
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/44; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/27; G01N21/274; G01N21/62; G01N21/63; G01N21/65; G01N2021/651

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 95 words
A method for calibrating a system adapted for spectrographic analysis of gaseous substances, comprising the steps of: using the system to generate a first spectrogram from air at a first number density level; using the system to generate a second spectrogram from air at a second number density level; using the first and second spectrogram of air to generate a background signal spectrogram; retrieving spectral data stored in the system; and using the background signal spectrogram, one of the spectrograms of air, and the retrieved spectral data to set an operating parameter of the system.
Claim 2
Independent Claim 95 words
A method for calibrating a system adapted for spectrographic analysis of gaseous substances, comprising the steps of: using the system to generate a first spectrogram from air at a first number density level; using the system to generate a second spectrogram from air at a second number density level; using the first and second spectrogram of air to generate a background signal spectrogram; retrieving spectral data stored in the system; and using the background signal spectrogram, one of the spectrograms of air, and the retrieved spectral data to set an operating parameter of the system.
Claim 3
Dependent Claim 52 words
A method as in claim 1 wherein the step of generating the first spectrogram from air includes the steps of: collecting ambient air; disposing the collected air within a chamber; stimulating the air disposed within the chamber to produce a spectral signal; and detecting the spectral signal to produce the first spectrogram.
Claim 4
Dependent Claim 19 words
A method as in claim 1 wherein the operating parameter of the system includes a frequency location alignment parameter.
Claim 5
Dependent Claim 20 words
A method as in claim 1 wherein the operating parameter of the system includes a gain parameter of the system.
Claim 6
Dependent Claim 21 words
A method as in claim 3 wherein the operating parameter of the system further includes a gain parameter of the system.
Claim 7
Independent Claim 74 words
A method for calibrating a system adapted for spectrographic analysis of gaseous substances, comprising the steps of: generating a first spectrogram from a gas at a first number density level; changing density of the gas from the first number density level to a second number density level; generating a second spectrogram of the gas at the second density level; using the first and second spectrogram to set an operating parameter of the spectrographic system.
Claim 8
Independent Claim 74 words
A method for calibrating a system adapted for spectrographic analysis of gaseous substances, comprising the steps of: generating a first spectrogram from a gas at a first number density level; changing density of the gas from the first number density level to a second number density level; generating a second spectrogram of the gas at the second density level; using the first and second spectrogram to set an operating parameter of the spectrographic system.
Claim 9
Dependent Claim 56 words
A method as in claim 6 wherein the step of using the first and second spectrogram to set an operating parameter of the spectrographic system includes the steps of: using the first and second spectrogram to generate a background signal spectrogram; and using the background signal spectrogram in setting the operating parameter of the spectrographic system.
Claim 10
Dependent Claim 20 words
A method as in claim 6 wherein the operating parameter of the spectrographic system includes a frequency location alignment parameter.
Claim 11
Dependent Claim 18 words
A method as in claim 6 wherein the operating parameter of the spectrographic system includes a gain parameter.
Claim 12
Dependent Claim 25 words
A method as in claim 6 wherein the second number density level differs from the first number density level by at least twenty five percent.
Claim 13
Dependent Claim 33 words
A method as in claim 6 wherein the step of changing density of the gas includes disposing the gas within a chamber so that the gas is at the second number density level.
Claim 14
Dependent Claim 50 words
A method as in claim 6 wherein the step of generating the first spectrogram includes: disposing the gas within a chamber so that the gas is at the first number density level; stimulating the gas to produce a spectral signal; and detecting the spectral signal to produce the first spectrogram.
Claim 15
Dependent Claim 44 words
A method as in claim 12 wherein the step of changing density of the gas includes partially evacuating the gas from the chamber, thereby changing density of the gas in the chamber from the first number density level to the second number density level.
Claim 16
Dependent Claim 45 words
A method as in claim 12 wherein the step of changing density of the gas includes disposing more of the gas within the chamber, thereby changing density of the gas in the chamber from the first number density level to the second number density level.
Claim 17
Dependent Claim 15 words
A method as in claim 6 wherein the gas is a mixture of constituent gasses.
Claim 18
Dependent Claim 14 words
A method as in claim 15 wherein the mixture of constituent gases is air.
Claim 19
Dependent Claim 18 words
A method as in claim 6 wherein the gas at the first number density level is ambient air.
Claim 20
Dependent Claim 19 words
A method as in claim 6 wherein the first and second spectrograms are generated by means of Raman spectroscopy.
Claim 21
Dependent Claim 21 words
A method as in claim 8 wherein the operating parameter of the system further includes a gain parameter of the system.
Claim 22
Independent Claim 93 words
An apparatus for calibrating a system adapted for spectrographic analysis of gaseous substances, the apparatus comprising: means coupled with the system for generating a first spectrogram from a gas at a first number density level; means coupled with the system for changing density of the gas from the first number density level to a second number density level; means coupled with the system for generating a second spectrogram of the gas at the second density level; and means using the first and second spectrogram for setting an operating parameter of the spectrographic system.
Claim 23
Independent Claim 93 words
An apparatus for calibrating a system adapted for spectrographic analysis of gaseous substances, the apparatus comprising: means coupled with the system for generating a first spectrogram from a gas at a first number density level; means coupled with the system for changing density of the gas from the first number density level to a second number density level; means coupled with the system for generating a second spectrogram of the gas at the second density level; and means using the first and second spectrogram for setting an operating parameter of the spectrographic system.

References Cited (Backward Citations)

US3728540A Cited
US4648714A Cited
US4692621A Cited
US4784486A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-08-22 1998-02-21 1998-08-23 $2000.00 Window Closed / Lapsed
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