US4087798A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device and method for determining the presence of resonant materials
Assignee: University of Akron
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Filing: 1976-03-17
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Granted: 1978-05-02
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Expires: 1996-03-17
Abstract
Abstract A spectroscopic refractometer has a plurality of resonant cavities through which the environment to be sampled may pass, including a first resonant cavity constructed and tuned to resonate at a transition frequency of the resonant material of interest and a second resonant cavity constructed and tuned to resonate at a nontransition frequency closely associated to the transition frequency to which the first resonant cavity is tuned. The resonant cavities are excited by electromagnetic oscillations corresponding in frequency to the transition and the nontransition frequency. A corrrelating parameter, such as frequency difference, is determined between the signals within the first and second resonant cavities, which in the absence of the resonant material of interest has a constant value. In the presence of the resonant material of interest a change in the value of the correlating parameter is detected and subsequently compared with the constant value of the correlating parameter so as to determine the presence of the resonant material of interest.
Inventors
- 👤 Donald C. Thorn
- 👤 Glenn A. Atwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:23
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/04
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
164 words
A method for determining the presence and unique identity of materials exhibiting resonant characteristics comprising the steps of: tuning a plurality of resonant cavities, at least a first said resonant cavity to a transition frequency of said resonant material and at least a second said resonant cavity to a nontransition frequency closely associated to said transition frequency; passing the resonant material through at least said first and second resonant cavities; exciting said first and second resonant cavities with electromagnetic oscillations corresponding in frequency to said transition and said nontransition frequency, respectively; determining the constant value of a correlating parameter between the signals within said first and said second resonant cavities existing in the absence of said resonant material; detecting the value of the correlating parameter between the signals within said first and said second resonant cavities existing in the presence of said resonant material; and comparing the values of said correlating parameter so as to determine the presence and unique identity of the material.
Claim 2
Independent Claim
164 words
A method for determining the presence and unique identity of materials exhibiting resonant characteristics comprising the steps of: tuning a plurality of resonant cavities, at least a first said resonant cavity to a transition frequency of said resonant material and at least a second said resonant cavity to a nontransition frequency closely associated to said transition frequency; passing the resonant material through at least said first and second resonant cavities; exciting said first and second resonant cavities with electromagnetic oscillations corresponding in frequency to said transition and said nontransition frequency, respectively; determining the constant value of a correlating parameter between the signals within said first and said second resonant cavities existing in the absence of said resonant material; detecting the value of the correlating parameter between the signals within said first and said second resonant cavities existing in the presence of said resonant material; and comparing the values of said correlating parameter so as to determine the presence and unique identity of the material.
Claim 3
Dependent Claim
24 words
A method, as in claim 1, wherein said transition frequency and said nontransition frequency are frequencies in the microwave region of the electromagnetic spectrum.
Claim 4
Dependent Claim
51 words
A method, as in claim 1, wherein the steps of determining said constant value of the correlating parameter and detecting the value of the correlating parameter include the respective steps of determining and detecting the magnitude of the difference frequencies between said electromagnetic oscillations within said first and second resonant cavities.
Claim 5
Dependent Claim
40 words
A method, as in claim 1, further comprising the step of preventing shifting of the frequencies at which said first and second resonant cavities are operating of such an extent that the presence of the material would be rendered indeterminable.
Claim 6
Dependent Claim
25 words
A method, as in claim 4, wherein the step of preventing includes conditioning the environment prior to its passing through said plurality of resonant cavities.
Claim 7
Independent Claim
241 words
A method for determining the presence and unique identity of materials exhibiting resonant characteristics comprising the steps of: tuning a plurality of resonant cavities, at least a first said resonant cavity to a transition frequency of said resonant material, at least a second said resonant cavity to a nontransition frequency closely associated to said transition frequency, and at least one sealed said resonant cavity to a frequency within the range including the said transition frequency and said nontransition frequency; passing the resonant material through at least said first and second resonant cavities; exciting said first and second resonant cavities with electromagnetic oscillations corresponding in frquency to said transition and said nontransition frequency, respectively exciting said sealed resonant cavity with electromagnetic oscillations having a frequency within the range including said transition frequency and said nontransition frequency; determining a constant value of a correlating parameter between the signals within the said first resonant cavity and said sealed resonant cavity and between said second resonant cavity and said sealed resonant cavity existing in the absence of said resonant material; detecting the change in the value of the correlating parameter between the signals within said first resonant cavity and said sealed resonant cavity and between said second resonant cavity and said sealed resonant cavity existing in the presence of said resonant material, and comparing the change in the values of said correlating parameter so as to determine the presence and unique identity of the material.
Claim 8
Independent Claim
241 words
A method for determining the presence and unique identity of materials exhibiting resonant characteristics comprising the steps of: tuning a plurality of resonant cavities, at least a first said resonant cavity to a transition frequency of said resonant material, at least a second said resonant cavity to a nontransition frequency closely associated to said transition frequency, and at least one sealed said resonant cavity to a frequency within the range including the said transition frequency and said nontransition frequency; passing the resonant material through at least said first and second resonant cavities; exciting said first and second resonant cavities with electromagnetic oscillations corresponding in frquency to said transition and said nontransition frequency, respectively exciting said sealed resonant cavity with electromagnetic oscillations having a frequency within the range including said transition frequency and said nontransition frequency; determining a constant value of a correlating parameter between the signals within the said first resonant cavity and said sealed resonant cavity and between said second resonant cavity and said sealed resonant cavity existing in the absence of said resonant material; detecting the change in the value of the correlating parameter between the signals within said first resonant cavity and said sealed resonant cavity and between said second resonant cavity and said sealed resonant cavity existing in the presence of said resonant material, and comparing the change in the values of said correlating parameter so as to determine the presence and unique identity of the material.
Claim 9
Dependent Claim
40 words
A method, as in claim 6, further comprising the step of preventing shifting of the frequencies at which said first and second resonant cavities are operating of such an extent that the presence of the material would be rendered indeterminable.
Claim 10
Dependent Claim
57 words
A method, as in claim 7, wherein the step of preventing includes retuning said first and second resonant cavities to said transition and nontransition frequencies respectively prior to the shifting of the frequencies at which said first and second resonant cavities are operating of such an extent that the presence of the material would be rendered indeterminable.
Claim 11
Independent Claim
125 words
A device for determining the presence and unique identity of materials exhibiting resonant characteristics in the presence of electromagnetic oscillations comprising: means to generate electromagnetic oscillations; a plurality of resonant cavity means through which the resonant material may pass and within which the resonant material may resonate, said resonant cavity means connected to said means to generate electromagnetic oscillations, and including at least a first said resonant cavity tuned to a transition frequency of the resonant material and at least a second said resonant cavity tuned to a nontransition frequency closely associated to said transition frequency; and detection means receiving said electromagnetic oscillations and detecting the values of a correlating parameter between at least said first resonant cavity and at least said second resonant cavity.
Claim 12
Independent Claim
125 words
A device for determining the presence and unique identity of materials exhibiting resonant characteristics in the presence of electromagnetic oscillations comprising: means to generate electromagnetic oscillations; a plurality of resonant cavity means through which the resonant material may pass and within which the resonant material may resonate, said resonant cavity means connected to said means to generate electromagnetic oscillations, and including at least a first said resonant cavity tuned to a transition frequency of the resonant material and at least a second said resonant cavity tuned to a nontransition frequency closely associated to said transition frequency; and detection means receiving said electromagnetic oscillations and detecting the values of a correlating parameter between at least said first resonant cavity and at least said second resonant cavity.
Claim 13
Dependent Claim
24 words
A device, as in claim 9, wherein said transition frequency and said nontransition frequency are frequencies in the microwave region of the electromagnetic spectrum.
Claim 14
Dependent Claim
30 words
A device, as in claim 9, further comprising alarm means to provide warning of the presence and unique identity of materials exhibiting resonance characteristics and connected to said detection means.
Claim 15
Dependent Claim
28 words
A device, as in claim 9, further comprising feedback means to stabilize said means to generate electromagnetic oscillations by feedback from said first and second microwave resonant cavities.
Claim 16
Dependent Claim
35 words
A device, as in claim 9, wherein said detection means includes at least one detector means for generating said correlating parameter and detector circuit means connected to said detection means for processing said correlating parameter.
Claim 17
Dependent Claim
40 words
A device, as in claim 9, further comprising conditioning means to prevent shifting of the frequencies at which said first and second resonant cavities are operating to such an extent that the presence of the material would be rendered indeterminable.
Claim 18
Dependent Claim
26 words
A device, as in claim 14, wherein said conditioning means includes means to condition the environment prior to its passing through said plurality of cavity means.
Claim 19
Dependent Claim
29 words
A device, as in claim 14, wherein said conditioning means includes circuit means receiving said detected values of the correlating parameter and retuning said first and second resonant cavities.
Claim 20
Independent Claim
177 words
A device for determining the presence and unique identity of materials exhibiting resonant characteristics in the presence of electromagnetic oscillations comprising: means to generate electromagnetic oscillations; a plurality of resonant cavity means through which the resonant material may pass and within which the resonant material may resonate, said resonant cavity means connected to said means to generate electromagnetic oscillations and including at least a first said resonant cavity tuned to a transition frequency of the resonant material and at least a second said resonant cavity tuned to a nontransition frequency closely associated to said transition frequency; conditioning means to prevent shifting of the frequencies at which said first and second resonant cavities are operated to such an extent that the presence of the material would be rendered indeterminable, said conditioning means including at least one sealed resonant cavity; and detection means receiving said electromagnetic oscillations and detecting the values of a correlating parameter between at least said first resonant cavity and said sealed resonant cavity, and at least said second resonant cavity and said sealed resonant cavity.
Claim 21
Independent Claim
177 words
A device for determining the presence and unique identity of materials exhibiting resonant characteristics in the presence of electromagnetic oscillations comprising: means to generate electromagnetic oscillations; a plurality of resonant cavity means through which the resonant material may pass and within which the resonant material may resonate, said resonant cavity means connected to said means to generate electromagnetic oscillations and including at least a first said resonant cavity tuned to a transition frequency of the resonant material and at least a second said resonant cavity tuned to a nontransition frequency closely associated to said transition frequency; conditioning means to prevent shifting of the frequencies at which said first and second resonant cavities are operated to such an extent that the presence of the material would be rendered indeterminable, said conditioning means including at least one sealed resonant cavity; and detection means receiving said electromagnetic oscillations and detecting the values of a correlating parameter between at least said first resonant cavity and said sealed resonant cavity, and at least said second resonant cavity and said sealed resonant cavity.
Claim 22
Dependent Claim
28 words
A device, as in claim 17, further comprising means to retun said first resonant cavity and said second resonant cavity to said transition and said nontransition frequencies respectively.
References Cited (Backward Citations)
US2792548A
Cited
US2580968A
Cited
US2849613A
Cited
US2933696A
Cited
US3458808A
Cited
US3998557A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |