Patent US5070246A successfully refreshed from Google Patents.
US5070246A
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US
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Spectrometer for measuring the concentration of components in a fluid stream and method for using same
Assignee: Ada Technologies Inc
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Filing: 1989-09-22
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Granted: 1991-12-03
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Expires: 2009-09-22
Abstract
Abstract A device and method for measuring the concentrations of components of a fluid stream. Preferably, the fluid stream is an in situ gas stream, such as a fossil fuel fired flue gas in a smoke stack. The measurements are determined from the intensity of radiation over a selected range of radiation wavelengths using peak-to-trough calculations. The need for a reference intensity is eliminated.
Inventors
- 👤 Michael D. Durham
- 👤 Donald H. Stedman
- 👤 Timothy G. Ebner
- 👤 Mark R. Burkhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:28
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01J; G01J3/00; G01J3/28; G01J3/2803; G01J3/42; G01N21/33; G01N21/35; G01N21/3504
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
91 words
A method for in situ measurement of at least one component in a gas stream comprising: a) passing radiation through an in situ gas stream, b) selecting at least one wavelength range in which said component absorbs radiation, c) measuring the amount of radiation which passes through said gas stream at a plurality of wavelengths within said selected wavelengths range, and d) calculating the concentration of said component by comparing the difference in the amount of radiation which passes through said gas at two selected points within said selected wavelength range.
Claim 2
Independent Claim
91 words
A method for in situ measurement of at least one component in a gas stream comprising: a) passing radiation through an in situ gas stream, b) selecting at least one wavelength range in which said component absorbs radiation, c) measuring the amount of radiation which passes through said gas stream at a plurality of wavelengths within said selected wavelengths range, and d) calculating the concentration of said component by comparing the difference in the amount of radiation which passes through said gas at two selected points within said selected wavelength range.
Claim 3
Dependent Claim
24 words
The method as claimed in claim 1 wherein said gas stream is a flue gas and the in situ environment is a smoke stack.
Claim 4
Dependent Claim
31 words
The method as claimed in claim 1 wherein said component is selected from the group consisting of NO, SO 2 , NH 3 , aromatic hydrocarbons, formaldehyde, ozone, chlorine and bromine.
Claim 5
Dependent Claim
82 words
The method as claimed in claim 1 wherein said step of calculating the concentration of the component comprises: a) determining a first wavelength at which minimum transmitted radiation occurs within said selected range, b) determining a second wavelength at which maximum transmitted radiation occurs within said selected range, c) determining the difference between said minimum transmitted radiation and said maximum transmitted radiation, and d) calculating the concentration of said component using reference data obtained from measurements performed on gases of known concentration.
Claim 6
Dependent Claim
139 words
The method as claimed in claim 1 wherein said step of calculating the concentration of a component comprises: a) determining a first wavelength at which a minimal amount of radiation is transmitted within said selected range, b) calculating a base line by performing a linear regression calculation on two groups of transmitted radiation values within said selected range, the first group of transmitted radiation values corresponding to wavelengths less than said first wavelength and at which high transmission occurs and the second group of transmitted radiation values corresponding to wavelengths greater than said first wavelength and at which high transmission occurs, c) determining the difference between said minimal transmitted radiation value and said base line at said first wavelength, and d) calculating the concentration of said component using reference data obtained from measurements performed on gases of known concentration.
Claim 7
Dependent Claim
27 words
The method as claimed in claim 1 wherein at least two wavelengths ranges are selected in order to measure at least two components in said gas stream.
Claim 8
Dependent Claim
33 words
The method as claimed in claim 1 wherein the concentration of NH 3 in a gas stream is measured and the selected wavelength range is from about 2040 Angstroms to about 2120 Angstroms.
Claim 9
Dependent Claim
52 words
The method as claimed in claim 7 wherein the concentration of NH 3 is calculated by employing both the difference in the amount of radiation which passes through said gas at two selected points within said wavelength range and a calibration curve of the type illustrated in FIGS. 4, 5 and 13.
Claim 10
Dependent Claim
32 words
The method as claimed in claim 1 wherein the concentration of NO in a gas stream is measured and the selected wavelength range is from about 2100 Angstroms to about 2200 Angstroms.
Claim 11
Dependent Claim
48 words
The method as claimed in claim 9 wherein the concentration of NO is calculated by employing both the difference in the amount of radiation which passes through said gas at two selected points within said wavelength range and a calibration curve of the type illustrated in FIG. 8.
Claim 12
Dependent Claim
33 words
The method as claimed in claim 1 wherein the concentration of SO 2 in a gas stream is measured and the selected wavelength range is from about 2270 Angstroms to about 2300 Angstroms.
Claim 13
Dependent Claim
49 words
The method as claimed in claim 11 wherein the concentration of SO 2 is calculated by employing both the difference in the amount of radiation which passes through said gas at two selected points within said wavelength range and a calibration curve of the type illustrated in FIG. 10.
Claim 14
Independent Claim
150 words
A device for in situ measurement of components in a gas stream comprising: a) a radiation source; b) a radiation detection means for measuring radiation transmitted through said gas stream at a plurality of wavelengths within at least one selected wavelength range, c) means for passing radiation from said radiation source through said in situ gas stream before impinging on said radiation detection means, wherein said means comprises components which are positionally fixed during the measuring of said radiation, d) calculation means for determining the concentration of a component in said gas stream by employing the transmitted radiation values obtained for said selected wavelength range to obtain a deference between a maximum transmitted radiation value and a minimum transmitted radiation value within said selected wavelength range and comparing said difference to calibration values obtained by measuring relative transmitted radiation values for gases of known concentration within said selected wavelength range.
Claim 15
Independent Claim
150 words
A device for in situ measurement of components in a gas stream comprising: a) a radiation source; b) a radiation detection means for measuring radiation transmitted through said gas stream at a plurality of wavelengths within at least one selected wavelength range, c) means for passing radiation from said radiation source through said in situ gas stream before impinging on said radiation detection means, wherein said means comprises components which are positionally fixed during the measuring of said radiation, d) calculation means for determining the concentration of a component in said gas stream by employing the transmitted radiation values obtained for said selected wavelength range to obtain a deference between a maximum transmitted radiation value and a minimum transmitted radiation value within said selected wavelength range and comparing said difference to calibration values obtained by measuring relative transmitted radiation values for gases of known concentration within said selected wavelength range.
Claim 16
Dependent Claim
28 words
The device as claimed in claim 13 wherein said components include NH 3 , NO and SO 2 which are individually or simultaneously present in said gas stream.
Claim 17
Dependent Claim
29 words
The device as claimed in claim 13 wherein said radiation detection means comprises a linear photodiode array having a resolution from about 1 to about 4 Angstroms per diode.
Claim 18
Dependent Claim
26 words
The device as claimed in claim 13 wherein said radiation detection means comprises a linear photodiode array having a resolution of about one Angstrom per diode.
Claim 19
Independent Claim
119 words
A method for calculating the concentration of a component in a fluid comprising: a) selecting a wavelength range, wherein said component absorbs radiation at some wavelengths within said wavelength range, b) passing radiation through said fluid, c) measuring the amount of radiation transmitted at wavelengths within said wavelength range, d) determining a first wavelength at which the minimum amount of radiation is transmitted within said wavelength range, e) calculating a base line for said wavelength range, said base line passing through points of relatively high transmitted of radiation values, f) calculating the difference between said base line and said minimum transmitted radiation point at said first wavelength, and g) calculating the concentration of the component based on said difference.
Claim 20
Independent Claim
119 words
A method for calculating the concentration of a component in a fluid comprising: a) selecting a wavelength range, wherein said component absorbs radiation at some wavelengths within said wavelength range, b) passing radiation through said fluid, c) measuring the amount of radiation transmitted at wavelengths within said wavelength range, d) determining a first wavelength at which the minimum amount of radiation is transmitted within said wavelength range, e) calculating a base line for said wavelength range, said base line passing through points of relatively high transmitted of radiation values, f) calculating the difference between said base line and said minimum transmitted radiation point at said first wavelength, and g) calculating the concentration of the component based on said difference.
Claim 21
Dependent Claim
33 words
The method as claimed in claim 17 wherein the concentration of NH 3 is a gas stream is calculated and the selected wavelength range is from about 2040 Angstroms to about 2120 Angstroms.
Claim 22
Dependent Claim
38 words
The method as claimed in claim 18 wherein the concentration of NH 3 is calculated by employing both the log values of said difference and a calibration curve of the type illustrated in FIGS. 4, 5 and 13.
Claim 23
Dependent Claim
85 words
The method as claimed in claim 17 wherein said component is NH 3 and said base line is calculated by performing a linear regression operation on a first group of selected points corresponding to transmitted radiation values for wavelengths in the range of from about 20 to about 50 Angstroms less than said first wavelength and a second group of selected points corresponding to transmitted radiation values for wavelengths in the range of from about 20 to about 50 Angstroms more than said first wavelength.
Claim 24
Dependent Claim
32 words
The method as claimed in claim 17 wherein the concentration of NO in a gas stream is calculated and the selected wavelength range is from about 2200 Angstroms to about 2300 Angstroms.
Claim 25
Dependent Claim
34 words
The method as claimed in claim 21 wherein the concentration of NO is calculated by employing both the log values of said difference and a calibration curve of the type illustrated in FIG. 8.
Claim 26
Dependent Claim
83 words
The method as claimed in claim 17 wherein said component is NO and said base line is calculated by performing a linear regression operation on a first group of selected points corresponding to transmitted radiation values for wavelengths in the range of from about 20 to about 50 Angstroms less than said wavelength and a second group of selected points corresponding to transmitted radiation values for wavelengths in the range of from about 20 to about 50 Angstroms more than said first wavelength.
Claim 27
Dependent Claim
34 words
The method as claimed in claim 17 wherein the concentration of SO 2 gas in a gas stream is calculated and the selected wavelength range is from about 2170 Angstroms to about 2200 Angstroms.
Claim 28
Dependent Claim
35 words
The method as claimed in claim 24 wherein the concentration of SO 2 is calculated by employing both the log values of said difference and a calibration curve of the type illustrated in FIG. 10.
Claim 29
Dependent Claim
85 words
The method as claimed in claim 17 wherein said component is SO 2 and said base line is calculated by performing a linear regression operation on a first group of selected points corresponding to transmitted radiation values for wavelengths in the range of from about 15 to about 25 Angstroms less than said first wavelength and a second group of selected points corresponding to transmitted radiation values for wavelengths in the range of from about 15 to about 25 Angstroms more than said first wavelength.
Claim 30
Independent Claim
91 words
A device for determining the concentrations of at least one component in a fluid comprising: a) a positionally fixed radiation source; b) a positionally fixed chromator, c) a positionally fixed filter, d) a positionally fixed radiation detection means capable of sensing the intensity of incident radiation within at least one selected wavelength range, and e) means to convert the output from the radiation detection means to a concentration for the desired component based upon a single reading of radiation intensities across said selected wavelength range and using a predetermined calibration curve.
Claim 31
Independent Claim
91 words
A device for determining the concentrations of at least one component in a fluid comprising: a) a positionally fixed radiation source; b) a positionally fixed chromator, c) a positionally fixed filter, d) a positionally fixed radiation detection means capable of sensing the intensity of incident radiation within at least one selected wavelength range, and e) means to convert the output from the radiation detection means to a concentration for the desired component based upon a single reading of radiation intensities across said selected wavelength range and using a predetermined calibration curve.
Claim 32
Dependent Claim
20 words
A device as claimed in claim 27 wherein said fluid is a gas and said component is NH 3 .
Claim 33
Dependent Claim
18 words
A device as claimed in claim 27 wherein said fluid is a gas and said component is NO.
Claim 34
Dependent Claim
20 words
A device as claimed in claim 27 wherein said fluid is a gas and said component is SO 2 .
Claim 35
Dependent Claim
33 words
A device as claimed in claim 27 wherein said radiation source comprises a deuterium lamp which produces ultraviolet and visible radiation in the wavelength region of from about 1900 to about 6000 Angstroms.
Claim 36
Dependent Claim
17 words
A device as claimed in claim 27 wherein said polychromator comprises a prism or an optical grating.
Claim 37
Dependent Claim
13 words
A device as claimed in claim 27 wherein said filter comprises a slit.
Claim 38
Dependent Claim
17 words
A device as claimed in claim 27 wherein said radiation detection means comprises a linear photodiode array.
Claim 39
Dependent Claim
33 words
A device as claimed in claim 27 wherein said radiation detection means comprises a linear photodiode array having a resolution effective for identifying appropriate peaks and preventing the undesirable blending of adjacent peaks.
Claim 40
Dependent Claim
29 words
A device as claimed in claim 27 wherein said radiation detection means comprises a linear photodiode array having a resolution from about 1 to about 4 Angstroms per diode.
Claim 41
Dependent Claim
26 words
A device as claimed in claim 27 wherein said radiation detection means comprises a linear photodiode array having a resolution of about one Angstrom per diode.
Claim 42
Independent Claim
85 words
A method for measuring the concentration of a component in a sample comprising: a) passing radiation through said sample, b) dispersing said radiation in order to generate a spectrum, c) measuring the intensity of a selected wavelength range within said spectrum after said radiation has passed through said sample, d) determining the difference between the maximum transmitted radiation and the minimum transmitted radiation within said selected range, e) calculating the concentration of said component by comparing said difference to previously determined differences for known concentrations.
Claim 43
Independent Claim
85 words
A method for measuring the concentration of a component in a sample comprising: a) passing radiation through said sample, b) dispersing said radiation in order to generate a spectrum, c) measuring the intensity of a selected wavelength range within said spectrum after said radiation has passed through said sample, d) determining the difference between the maximum transmitted radiation and the minimum transmitted radiation within said selected range, e) calculating the concentration of said component by comparing said difference to previously determined differences for known concentrations.
Claim 44
Dependent Claim
46 words
The method as claimed in claim 38 wherein said step of measuring the intensity of a selected wavelength range within said spectrum is accomplished using a radiation detection means comprising a linear photodiode array having a resolution of from 1 to about 4 Angstroms per diode.
Claim 45
Dependent Claim
42 words
The method as claimed in claim 38 wherein said step of measuring the intensity of a selected wavelength range within said spectrum is accomplished using a radiation detector comprising a linear photodiode array having a resolution of approximately one Angstrom per diode.
Claim 46
Independent Claim
169 words
A method for determining the concentration of NH 3 , NO and SO 2 in a gas stream comprising: a) measuring the intensity of radiation passing through the gas stream at wavelengths which correspond to absorption by SO 2 between about 2170 Angstroms and about 2200 Angstroms, b) employing peak-to-trough calculations to determine the concentration of SO 2 , c) determining the spectrum corresponding to the SO 2 alone based upon the peak-to-trough calculations and predetermined calibration curves, d) mathematically subtracting the spectrum due to SO 2 alone from the overall spectrum, e) measuring the intensity of radiation passing through the gas stream at wavelengths which correspond to absorption by NH 3 between about 2040 Angstroms and about 2120 Angstroms, f) employing peak-to-trough calculations to determine the concentration of NH 3 , g) measuring the intensity of radiation passing through the gas stream at wavelength which corresponds to absorption by NO between about 2200 Angstroms and about 2300 Angstroms, i) employing peak-to-trough calculations to determine the concentration of NO.
Claim 47
Independent Claim
169 words
A method for determining the concentration of NH 3 , NO and SO 2 in a gas stream comprising: a) measuring the intensity of radiation passing through the gas stream at wavelengths which correspond to absorption by SO 2 between about 2170 Angstroms and about 2200 Angstroms, b) employing peak-to-trough calculations to determine the concentration of SO 2 , c) determining the spectrum corresponding to the SO 2 alone based upon the peak-to-trough calculations and predetermined calibration curves, d) mathematically subtracting the spectrum due to SO 2 alone from the overall spectrum, e) measuring the intensity of radiation passing through the gas stream at wavelengths which correspond to absorption by NH 3 between about 2040 Angstroms and about 2120 Angstroms, f) employing peak-to-trough calculations to determine the concentration of NH 3 , g) measuring the intensity of radiation passing through the gas stream at wavelength which corresponds to absorption by NO between about 2200 Angstroms and about 2300 Angstroms, i) employing peak-to-trough calculations to determine the concentration of NO.
Claim 48
Dependent Claim
33 words
The method as claimed in claim 41 further comprising the step of chemically removing SO 2 from the gas stream by selective scrubbing prior to the calculation of NH 3 and NO concentration.
References Cited (Backward Citations)
US2170435A
Cited
US2620444A
Cited
US2690093A
Cited
US3640625A
Cited
US3637310A
Cited
US3732017A
Cited
US3702736A
Cited
US3929398A
Cited
US3880523A
Cited
US3893770A
Cited
US3973849A
Cited
US4054389A
Cited
US4158505A
Cited
US4571074A
Cited
US4563585A
Cited
US4566792A
Cited
US4678917A
Cited
US4746793A
Cited
US4914719A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |