US4999013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controllable interferometer
Assignee: ABB Training Center GmbH and Co KG
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Filing: 1989-04-14
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Granted: 1991-03-12
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Expires: 2009-04-14
Abstract
Abstract Interferometric equipment for detecting a substance having a structure preferably a periodic or quasiperiodic absorption spectrum; the equipment includes a source of radiation, a path for that radiation that includes a sample cell with the substance to be detected, an interference filter and a detector, and is improved in that the interference filter is constructed as an electrically tunable filter, including a plate or cell element with semitransparent reflective boundaries serving as electrodes; an electrical voltage is applied to said electrodes such that the transmission characteristics of the filter is varied and the amplitude of the voltage as applied to these electrodes is an indication of that variation; and the thickness of the plate or cell is selected to meet one of the following criteria (i) a distance between the interference lines produced equals a distance of absorption lines within a periodic absorption spectrum of said substance; (ii) the equipment causes a line to be separated from the radiation having a bandwidth which is small as compared with a spacing between two absorption lines of the substance to be found (iii) the equipment causes a line to be separated from the radiation, to overlap an edge of an absorption band of the substance to be directed.
Inventors
- 👤 Michael Zoechbauer
- 👤 Walter Fabinski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:55
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01J; G01J3/00; G01J3/12; G01J3/26; G01N2201/00; G01N2201/06; G01N2201/067
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
135 words
Interferometric equipment for detecting a substance having a structure yielding a periodic or quasiperiodic absorption spectrum, the equipment including a source of radiation, a path for that radiation that includes the substance to be detected, an interference filter and a detector, the improvement comprising: the interference filter being constructed as an electrically tunable filter including a plate or cell element with semitransparent reflective boundaries serving as electrodes; means for providing an electrical voltage to said electrodes such that the transmission characteristics of the filter is varied and the amplitude of the voltage as applied to these electrodes is an indication of that variation; and the thickness of the plate or cell providing for a distance between the interference lines as produced equaling a distance of absorption lines within a periodic absorption spectrum of said substance.
Claim 2
Dependent Claim
135 words
Interferometric equipment for detecting a substance having a structure yielding a periodic or quasiperiodic absorption spectrum, the equipment including a source of radiation, a path for that radiation that includes the substance to be detected, an interference filter and a detector, the improvement comprising: the interference filter being constructed as an electrically tunable filter including a plate or cell element with semitransparent reflective boundaries serving as electrodes; means for providing an electrical voltage to said electrodes such that the transmission characteristics of the filter is varied and the amplitude of the voltage as applied to these electrodes is an indication of that variation; and the thickness of the plate or cell providing for a distance between the interference lines as produced equaling a distance of absorption lines within a periodic absorption spectrum of said substance.
Claim 3
Dependent Claim
17 words
Interferometer as in claim 1, said cell being a solid plate having front faces covered with electrodes.
Claim 4
Dependent Claim
16 words
Interferometer as in claim 1, said filter being a cell filled with a double refracting liquid.
Claim 5
Dependent Claim
14 words
Interferometer as in claim 1, there being plural differently attuned filters in said path.
Claim 6
Dependent Claim
153 words
Interferometric equipment for detecting a substance having a structure yielding a periodic or quasiperiodic absorption spectrum, the equipment including a source of radiation, a path for that radiation that includes the substance to be detected, an interference filter and a detector, the improvement comprising: the interference filter being constructed as an electrically tunable filter including a plate or cell element with semitransparent reflective boundaries serving as electrodes; means for providing an electrical voltage to said electrodes such that the transmission characteristics of the filter is varied and the amplitude of the voltage as applied to these electrodes is an indication of that variation; and the thickness of the plate or cell being such that the equipment by operation of the plate or cell causes a line to be separated from the radiation having a bandwidth which is small as compared with a spacing between two absorption lines of the substance to be found.
Claim 7
Dependent Claim
153 words
Interferometric equipment for detecting a substance having a structure yielding a periodic or quasiperiodic absorption spectrum, the equipment including a source of radiation, a path for that radiation that includes the substance to be detected, an interference filter and a detector, the improvement comprising: the interference filter being constructed as an electrically tunable filter including a plate or cell element with semitransparent reflective boundaries serving as electrodes; means for providing an electrical voltage to said electrodes such that the transmission characteristics of the filter is varied and the amplitude of the voltage as applied to these electrodes is an indication of that variation; and the thickness of the plate or cell being such that the equipment by operation of the plate or cell causes a line to be separated from the radiation having a bandwidth which is small as compared with a spacing between two absorption lines of the substance to be found.
Claim 8
Dependent Claim
17 words
Interferometer as in claim 5, said cell being a solid plate having front faces covered with electrodes.
Claim 9
Dependent Claim
16 words
Interferometer as in claim 5, said filter being a cell filled with a double refracting liquid.
Claim 10
Dependent Claim
14 words
Interferometer as in claim 5, there being plural differently attuned filters in said path.
Claim 11
Dependent Claim
138 words
Interferometric equipment for detecting a substance having a structure yielding a periodic or quasiperiodic absorption spectrum, the equipment including a source of radiation, a path for that radiation that includes the substance to be detected, an interference filter and a detector, the improvement comprising: the interference filter being constructed as an electrically tunable filter including a plate or cell element with semitransparent reflective boundaries serving as electrodes; means for providing an electrical voltage to said electrodes such that the transmission characteristics of the filter is varied and the amplitude of the voltage as applied to these electrodes is an indication of that variation; and such that the equipment by operation of the plate or cell causes a line to be separated from the radiation, to overlap an edge of the absorption band of the substance to be detected.
Claim 12
Dependent Claim
138 words
Interferometric equipment for detecting a substance having a structure yielding a periodic or quasiperiodic absorption spectrum, the equipment including a source of radiation, a path for that radiation that includes the substance to be detected, an interference filter and a detector, the improvement comprising: the interference filter being constructed as an electrically tunable filter including a plate or cell element with semitransparent reflective boundaries serving as electrodes; means for providing an electrical voltage to said electrodes such that the transmission characteristics of the filter is varied and the amplitude of the voltage as applied to these electrodes is an indication of that variation; and such that the equipment by operation of the plate or cell causes a line to be separated from the radiation, to overlap an edge of the absorption band of the substance to be detected.
Claim 13
Dependent Claim
17 words
Interferometer as in claim 9, said cell being a solid plate having front faces covered with electrodes.
Claim 14
Dependent Claim
16 words
Interferometer as in claim 9, said filter being a cell filled with a double refracting liquid.
Claim 15
Dependent Claim
14 words
Interferometer as in claim 9, there being plural differently attunded filters in said path.
References Cited (Backward Citations)
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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) | 1994-03-11 | 1994-09-10 | 1995-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-11 | 1998-09-10 | 1999-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-11 | 2002-09-10 | 2003-03-12 | $7700.00 | Window Closed / Lapsed |