US4827121A
Expired / Lapsed
US
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System for detecting chemical changes in materials by embedding in materials an unclad fiber optic sensor section
Assignee: Honeywell Measurex Corp
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Filing: 1988-02-24
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Granted: 1989-05-02
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Expires: 2008-02-24
Abstract
Abstract A system for detecting chemical characteristics within a material includes an optical fiber having a relatively short unclad sensor section for embedding in a material, a source of infrared radiation to direct infrared radiation into the fiber, and an optical decoder connected to the fiber to detect the spectrum of infrared radiation absorbed by the material in which the sensor section is embedded.
Inventors
- 👤 Warren D. Vidrine, Jr.
- 👤 Mark S. Roth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:10
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/55; G01N21/552; G01N21/25; G01N21/31; G01N21/35; G01N2021/3595; G01N21/41; G01N21/43; G01N21/431; G01N2021/432
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
79 words
A system for detecting chemical characteristics within a material comprising: an optical fiber embedded in a material, the fiber having an unclad sensor section; source means connected to direct optical radiation into the fiber; encoding means to modulate the optical radiation; and spectrum analyzer means connected to the fiber to detect at least a part of the spectrum of the modulated optical radiation and, thereby, to detect chemical characteristics of the material in which the sensor section is embedded.
Claim 2
Independent Claim
79 words
A system for detecting chemical characteristics within a material comprising: an optical fiber embedded in a material, the fiber having an unclad sensor section; source means connected to direct optical radiation into the fiber; encoding means to modulate the optical radiation; and spectrum analyzer means connected to the fiber to detect at least a part of the spectrum of the modulated optical radiation and, thereby, to detect chemical characteristics of the material in which the sensor section is embedded.
Claim 3
Dependent Claim
47 words
A system according to claim 1 wherein the unclad sensor section comprises a section between the ends of the fiber, and the source of means is connected to one end of the fiber and the spectrum analyzer means is connected to the other end of the fiber.
Claim 4
Dependent Claim
38 words
A system according to claim 1 wherein the unclad sensor section is at the end of the fiber, and the source means of infrared radiation and the spectrum analyzer are connected to the same end of the fiber.
Claim 5
Dependent Claim
16 words
A system according to claim 1 wherein the optical fiber extends outside the spectrum analyzer means.
Claim 6
Dependent Claim
20 words
A system according to claim 3 wherein the tip of the unclad sensor section of the fiber is generally pointed.
Claim 7
Dependent Claim
16 words
A system according to claim 1 wherein the spectrum analyzer means comprises a Fourier transform analyzer.
Claim 8
Dependent Claim
13 words
A system according to claim 1 wherein the encoding means comprises an interferometer.
Claim 9
Dependent Claim
15 words
A system according to claim 1 wherein unclad sensor section is formed from chalcogenide glass.
Claim 10
Dependent Claim
14 words
A system according to claim 8 wherein the chalcogenide glass is arsenic germanium-selenide glass.
Claim 11
Dependent Claim
16 words
A system according to claim 1 wherein the sensor section is formed from metal floride glass.
Claim 12
Independent Claim
94 words
A system for providing in-situ detection of the chemical state within a fiber-reinforced composite material, comprising: an optical fiber embedded in the fiber-reinforced composite material, the fiber having an unclad sensor section and the remainder of the fiber being clad; a light source connected to direct infrared radiation into the fiber; a detector connected to detect infrared radiation emerging from an end of the fiber; and a spectrum analyzer connected to the detector for measuring at least a part of the spectrum of infrared radiation absorbed by the composite material adjacent the sensor section.
Claim 13
Independent Claim
94 words
A system for providing in-situ detection of the chemical state within a fiber-reinforced composite material, comprising: an optical fiber embedded in the fiber-reinforced composite material, the fiber having an unclad sensor section and the remainder of the fiber being clad; a light source connected to direct infrared radiation into the fiber; a detector connected to detect infrared radiation emerging from an end of the fiber; and a spectrum analyzer connected to the detector for measuring at least a part of the spectrum of infrared radiation absorbed by the composite material adjacent the sensor section.
Claim 14
Dependent Claim
45 words
A system according to claim 11 wherein the unclad sensor section comprises a section intermediate the ends of the fiber, and the light source is connected to one end of the fiber and the spectrum analyzer is connected to the other end of the fiber.
Claim 15
Dependent Claim
18 words
A system according to claim 11 wherein the unclad sensor section is at the end of the fiber.
Claim 16
Dependent Claim
29 words
A system according to claim 13 wherein the light source and the spectrum analyzer are in optical communication with the same end of the fiber via a beam splitter.
Claim 17
Dependent Claim
15 words
A system according to claim 11 wherein the spectrum analyzer comprises a Fourier transform analyzer.
Claim 18
Dependent Claim
19 words
A system according to claim 11 further including an interferometer disposed between the sensor section and the spectrum analyzer.
Claim 19
Dependent Claim
70 words
A process for detecting chemical characteristics within a material, comprising the steps of: forming an optical fiber having an unclad sensor section; embedding the sensor section of the optical fiber in a material to be analyzed; directing light into the fiber; and operating a spectrum analyzer connected to the fiber to analyze at least a part of the spectrum of infrared radiation absorbed by the material adjacent the sensor section.
Claim 20
Dependent Claim
70 words
A process for detecting chemical characteristics within a material, comprising the steps of: forming an optical fiber having an unclad sensor section; embedding the sensor section of the optical fiber in a material to be analyzed; directing light into the fiber; and operating a spectrum analyzer connected to the fiber to analyze at least a part of the spectrum of infrared radiation absorbed by the material adjacent the sensor section.
Claim 21
Dependent Claim
14 words
A process according to claim 17 wherein the material is a thermosettable matrix resin.
Claim 22
Dependent Claim
15 words
A process according to claim 18 wherein the analyzer is operated while curing the resin.
Claim 23
Dependent Claim
17 words
A process according to claim 19 wherein the analyzer measures the degree of cross-linking of the resin.
Claim 24
Dependent Claim
26 words
A process according to claim 17 wherein a plurality of the optical fibers, each having a sensor section, are embedded in the materials at selected locations.
Claim 25
Dependent Claim
18 words
A process according to claim 17 wherein the material to be analyzed is located external of the analyzer.
Claim 26
Dependent Claim
15 words
A process according to claim 22 wherein the analyzer is a Fourier transform infrared analyzer.
Claim 27
Dependent Claim
15 words
A process according to claim 23 wherein the analyzed radiation is in the mid-infrared spectrum.
Claim 28
Dependent Claim
20 words
A process according to claim 24 wherein the wavelengths of analyzed radiation ranges from about five to about fifteen microns.
Claim 29
Dependent Claim
17 words
A process according to claim 25 wherein the spectrum analysis is accomplished by measuring attenuated total reflection.
Claim 30
Dependent Claim
42 words
A process according to claim 17 wherein the unclad sensor section is connected between the ends of the fiber, and light is directed into one end of the fiber and the spectrum analyzer is connected to the other end of the fiber.
Claim 31
Dependent Claim
18 words
A process according to claim 17 wherein the unclad sensor section is at the end of the fiber.
Claim 32
Dependent Claim
18 words
A process according to claim 17 wherein the core of the optical fiber is formed from chalcogenide glass.
Claim 33
Dependent Claim
19 words
A process according to claim 17 wherein the core of the optical fiber is formed from metal floride glass.
Claim 34
Dependent Claim
89 words
A process for providing in-situ detection of chemical conditions within a fiber-reinforced composite material during curing, comprising: embedding an optical fiber in the fiber-reinforced composite material with at least one end of the fiber extending from the material, the fiber having an unclad sensor section and the remainder of the fiber being clad; connecting a source of infrared radiation to the fiber; and connecting a Fourier transform spectrum analyzer to the fiber for detecting the spectrum of infrared radiation absorbed by the composite material adjacent the unclad sensor section.
Claim 35
Dependent Claim
89 words
A process for providing in-situ detection of chemical conditions within a fiber-reinforced composite material during curing, comprising: embedding an optical fiber in the fiber-reinforced composite material with at least one end of the fiber extending from the material, the fiber having an unclad sensor section and the remainder of the fiber being clad; connecting a source of infrared radiation to the fiber; and connecting a Fourier transform spectrum analyzer to the fiber for detecting the spectrum of infrared radiation absorbed by the composite material adjacent the unclad sensor section.
Claim 36
Dependent Claim
19 words
A process according to claim 31 wherein the unclad sensor section is formed by removing cladding from the fiber.
Claim 37
Dependent Claim
24 words
A process according to claim 32 wherein the unclad sensor section is formed by fusing an unclad optical fiber to a clad optical fiber.
Claim 38
Dependent Claim
18 words
A process according to claim 32 wherein the unclad sensor section is at the end of the fiber.
Claim 39
Dependent Claim
18 words
A process according to claim 32 wherein the unclad sensor section is between the ends of the fiber.
Claim 40
Dependent Claim
50 words
A sensor for use with a spectrum analyzer for detecting the chemical state of materials external to the spectrometer comprising: an optical fiber having an unclad sensor section for insertion into a material whose chemical state is to be measured and an end adapted for connection to a spectrum analyzer.
Claim 41
Dependent Claim
50 words
A sensor for use with a spectrum analyzer for detecting the chemical state of materials external to the spectrometer comprising: an optical fiber having an unclad sensor section for insertion into a material whose chemical state is to be measured and an end adapted for connection to a spectrum analyzer.
Claim 42
Dependent Claim
21 words
A sensor according to claim 36 wherein the material comprising the sensor section is compatible with Fourier transform infrared spectrum analyzer.
References Cited (Backward Citations)
US4608344A
Cited
US4639594A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |