Patent US4837438A successfully refreshed from Google Patents.
US4837438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct infrared measurement of homogenous mixtures
Assignee: ABB Automation Inc
•
Filing: 1987-06-17
•
Granted: 1989-06-06
•
Expires: 2007-06-17
Abstract
Abstract Apparatus and associated methods for measuring the polymer content of a mixture having polymer and cellulose components. Infrared absorption means are employed to derive a measurement of that fraction of the combined weights of polymer and cellulose components which is accounted for by the polymer.
Inventors
- 👤 Steven P. Sturm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:56
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N33/00; G01N33/34; G01N33/346; G01N21/3563
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
143 words
An apparatus for directly measuring the polymer content of a homogeneous mixture having both polymer and cellulose components, comprising: (a) source means for directing infrared radiation onto a portion of the mixture; (b) detector means for detecting infrared radiation of two sets of wavelengths after the radiation has interacted with the mixture, the first set including wavelengths that have about the same absorption coefficient for the cellulose component but have substantially different absorption coefficients for the polymer component, the second set including wavelengths that have about the same absorption coefficient for the polymer component but have substantially different absorption coefficients for the cellulose component, the detector means produces detector responses to the radiation corresponding to the two sets, wherein the responses are processed to produce a measurement of the fraction of polymer and cellulose components which is accounted for by the polymer component.
Claim 2
Independent Claim
143 words
An apparatus for directly measuring the polymer content of a homogeneous mixture having both polymer and cellulose components, comprising: (a) source means for directing infrared radiation onto a portion of the mixture; (b) detector means for detecting infrared radiation of two sets of wavelengths after the radiation has interacted with the mixture, the first set including wavelengths that have about the same absorption coefficient for the cellulose component but have substantially different absorption coefficients for the polymer component, the second set including wavelengths that have about the same absorption coefficient for the polymer component but have substantially different absorption coefficients for the cellulose component, the detector means produces detector responses to the radiation corresponding to the two sets, wherein the responses are processed to produce a measurement of the fraction of polymer and cellulose components which is accounted for by the polymer component.
Claim 3
Dependent Claim
22 words
An apparatus as in claim 1 further comprising means for processing the detector responses to produce a measurement of the polymer fraction.
Claim 4
Dependent Claim
106 words
An apparatus as in claim 2 wherein the processing means employs first, second, and third ratio forming operations, the first ratio forming operation forming a function of the transmittances of radiations in the first set to form a first response, the second ratio forming operation forming a function of the transmittances of radiations in the second set to produce a second response, and the third ratio forming operation forming a function of the ratio of the first and second responses to produce a third response that is used in conjunction with calibration data to produce a measurement response expressive of the polymer fraction of the mixture.
Claim 5
Dependent Claim
33 words
An apparatus as in claim 3 wherein the first set includes wavelengths of about 2.38 microns and about 2.10 microns, and the second set includes wavelengths of about 1.80 microns and 2.10 microns.
Claim 6
Independent Claim
137 words
A method for directly measuring the polymer content of a homogeneous mixture having both polymer and cellulose components, comprising the steps of: (a) directing infrared radiation from a source thereof onto a portion of the mixture; (b) detecting infrared radiation of two sets of wavelengths after the radiation has interacted with the mixture, the first set having about the same absorption coefficient for the cellulose component but having substantially different absorption coefficients for the polymer component, the second set having about the same absorption coefficient for the polymer component but having substantially different absorption coefficients for the cellulose component, to produce detector responses for each wavelength of the two sets; (c) processing the detector responses to produce a measurement response expressive of the fraction of polymer and cellulose components which is accounted for by the polymer component.
Claim 7
Independent Claim
137 words
A method for directly measuring the polymer content of a homogeneous mixture having both polymer and cellulose components, comprising the steps of: (a) directing infrared radiation from a source thereof onto a portion of the mixture; (b) detecting infrared radiation of two sets of wavelengths after the radiation has interacted with the mixture, the first set having about the same absorption coefficient for the cellulose component but having substantially different absorption coefficients for the polymer component, the second set having about the same absorption coefficient for the polymer component but having substantially different absorption coefficients for the cellulose component, to produce detector responses for each wavelength of the two sets; (c) processing the detector responses to produce a measurement response expressive of the fraction of polymer and cellulose components which is accounted for by the polymer component.
Claim 8
Dependent Claim
17 words
A method as in claim 5 wherein the steps are performed during continuous production of the mixture.
Claim 9
Dependent Claim
18 words
A method as in claim 6 wherein the mixture is in the form of a sheet of paper.
Claim 10
Dependent Claim
21 words
A method as in claim 7 further comprising the step of comparing the measurement response to a target polymer fraction value.
Claim 11
Dependent Claim
33 words
A method as in claim 8 further comprising the step of communicating adjustment signals to a process control unit in response to deviations of the measurement response from the target polymer fraction value.
Claim 12
Dependent Claim
24 words
A method as in claim 9 further comprising the step of controlling the polymer fraction of the sheet in response to the adjustment signals.
Claim 13
Dependent Claim
34 words
A method as in claim 10 wherein the first set includes wavelengths of about 2.38 microns and about 2.10 microns and the second set includes wavelengths of about 1.80 microns and about 2.10 microns.
References Cited (Backward Citations)
US3076723A
Cited
US3448268A
Cited
US4363968A
Cited
US4300049A
Cited
US4582520A
Cited
US4577104A
Cited
US4755678A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |