US4602160A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Infrared constituent analyzer and control system
Assignee: Sentrol Systems Ltd
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Filing: 1983-09-28
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Granted: 1986-07-22
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Expires: 2003-09-28
Abstract
Abstract Monochromatic infrared radiation of variable wavelengths between 1.0 and 3.5 microns is directed upon a portion of a moving web, and the spectra of infrared radiation reflected from the web portion and of radiation transmitted through the web portion are separately measured by sensors located on both sides of the web. These spectra are combined to provide an absorption spectrum insensitive to any elastic scattering that is also present. Measures of the contents of the web constituents are generated by least-square fitting the individual absorption spectra of the constituents to the measured absorption spectrum of the web. Means for calibrating the reflectance and transmittance measurements and for keeping the sensor viewing windows free of dirt and dust are also disclosed.
Inventors
- 👤 John W. MacTaggart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:18
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/84; G01N21/86; G01N33/00; G01N33/34; G01N33/346; G01J; G01J3/00; G01J3/12; G01J2003/1226; G01J2003/123; G01J2003/1234; G01N21/01; G01N21/15; G01N2021/151; G01N21/55; G01N2021/558; G01N2021/8609; G01N2021/8618; G01N2201/00; G01N2201/06; G01N2201/065; G01N2201/12; G01N2201/127; G01N2201/12723
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
103 words
Apparatus for measuring a constituent of a material including in combination means for directing infrared radiation upon a portion of said material, means for measuring infrared radiation reflected from said portion to produce a reflection signal, means for measuring infrared radiation transmitted through said portion to produce a transmission signal, said transmission signal having a dependence on elastic scattering of said radiation by said material, means responsive to said transmission signal for generating an indication of the content of said constituent, and means responsive to said reflection signal for correcting said content indication for the dependence of said transmission signal on elastic scattering.
Claim 2
Dependent Claim
103 words
Apparatus for measuring a constituent of a material including in combination means for directing infrared radiation upon a portion of said material, means for measuring infrared radiation reflected from said portion to produce a reflection signal, means for measuring infrared radiation transmitted through said portion to produce a transmission signal, said transmission signal having a dependence on elastic scattering of said radiation by said material, means responsive to said transmission signal for generating an indication of the content of said constituent, and means responsive to said reflection signal for correcting said content indication for the dependence of said transmission signal on elastic scattering.
Claim 3
Dependent Claim
47 words
Apparatus as in claim 1 in which said constituent has predetermined absorption and scattering coefficients, said generating means comprising means responsive to said measuring means for deriving a quantity dependent only on said absorption coefficient and means for generating said indication as a function of said quantity.
Claim 4
Dependent Claim
37 words
Apparatus as in claim 1 in which said measuring means respectively comprise means for measuring the spectrum of infrared radiation reflected from said portion and means for measuring the spectrum of infrared radiation transmitted through said portion.
Claim 5
Dependent Claim
71 words
Apparatus as in claim 1 in which said measuring means respectively comprise means for measuring the spectrum of infrared radiation reflected from said portion and means for measuring the spectrum of infrared radiation transmitted through said portion, said generating means comprising means responsive to said measuring means for determining the absorption spectrum of said portion of said material and means for generating said indication as a function of said absorption spectrum.
Claim 6
Dependent Claim
92 words
Apparatus as in claim 1 in which said measuring means respectively comprise means for measuring the spectrum of infrared radiation reflected from said portion and means for measuring the spectrum of infrared radiation transmitted through said portion, said generating means comprising means responsive to said measuring means for determining the measured absorption spectrum of said material and means for determining from said measured absorption spectrum that estimated constituent content producing a minimum deviation between the predicted absorption spectrum of said material with said content of said constituent and said measured absorption spectrum.
Claim 7
Independent Claim
100 words
A method of measuring a constituent of a material including the steps of directing infrared radiation upon a portion of said material, obtaining a measurement of infrared radiation reflected from said portion, obtaining a measurement of infrared radiation transmitted through said portion, said transmitted radiation measurement having a dependence on elastic scattering of said radiation by said material, generating an indication of the content of said constituent of said material in accordance with said transmitted radiation measurement, and correcting said content indication for the dependence of said transmitted radiation measurement on elastic scattering in accordance with said reflected radiation measurement.
Claim 8
Independent Claim
100 words
A method of measuring a constituent of a material including the steps of directing infrared radiation upon a portion of said material, obtaining a measurement of infrared radiation reflected from said portion, obtaining a measurement of infrared radiation transmitted through said portion, said transmitted radiation measurement having a dependence on elastic scattering of said radiation by said material, generating an indication of the content of said constituent of said material in accordance with said transmitted radiation measurement, and correcting said content indication for the dependence of said transmitted radiation measurement on elastic scattering in accordance with said reflected radiation measurement.
Claim 9
Dependent Claim
45 words
A method as in claim 6 in which said constituent has predetermined absorption and scattering coefficients, said generating step including the steps of deriving from said measurements a quantity dependent only on said absorption coefficient and generating said indication as a function of said quantity.
Claim 10
Dependent Claim
13 words
A method as in claim 6 in which said measurements are spectrum measurements.
Claim 11
Dependent Claim
48 words
A method as in claim 6 in which said measurements are spectrum measurements, said generating step including the steps of determining the absorption spectrum of said portion of said material as a function of said spectrum measurements and generating said indication as a function of said absorption spectrum.
Claim 12
Dependent Claim
69 words
A method as in claim 6 in which said measurements are spectrum measurements, said generating step including the steps of determining the measured absorption spectrum of said material as a function of said spectrum measurements and determining from said measured absorption spectrum that estimated constituent content producing a minimum deviation between the predicted absorption spectrum of said material with said content of said constituent and said measured absorption spectrum.
Claim 13
Dependent Claim
113 words
Apparatus for measuring the content of a constituent of a web of material including in combination means for irradiating said web with infrared radiation, means for measuring the intensity of infrared radiation transmitted through said web to produce a transmission signal, said transmission signal having a dependence on elastic scattering of said radiation by material in said web, means for measuring the intensity of infrared radiation reflected from said web to produce a reflection signal, means responsive to said transmission signal for generating an indication of the content of said constituent, and means responsive to said reflection signal for correcting said content indication for the dependence of said transmission signal on elastic scattering.
Claim 14
Dependent Claim
113 words
Apparatus for measuring the content of a constituent of a web of material including in combination means for irradiating said web with infrared radiation, means for measuring the intensity of infrared radiation transmitted through said web to produce a transmission signal, said transmission signal having a dependence on elastic scattering of said radiation by material in said web, means for measuring the intensity of infrared radiation reflected from said web to produce a reflection signal, means responsive to said transmission signal for generating an indication of the content of said constituent, and means responsive to said reflection signal for correcting said content indication for the dependence of said transmission signal on elastic scattering.
Claim 15
Dependent Claim
25 words
Apparatus as in claim 11 in which each of said measuring means measures the intensity of a narrow band of radiation emanating from said web.
Claim 16
Dependent Claim
26 words
Apparatus as in claim 11 in which each of said measuring means measures the intensity of an essentially monochromatic band of radiation emanating from said web.
Claim 17
Dependent Claim
27 words
Apparatus as in claim 11 in which each of said measuring means measures the intensities of a plurality of narrow bands of radiation emanating from said web.
Claim 18
Dependent Claim
22 words
Apparatus as in claim 11 in which each of said measuring means measures the spectrum of infrared radiation emanating from said web.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |