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US5545897A
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Optically-based chemical detection system
Assignee: Raytheon Co
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Filing: 1994-10-04
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Granted: 1996-08-13
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Expires: 2014-10-04
Abstract
Abstract An in-situe chemical gas or fluid analyzer for vehicles, industrial, environmental and process control applications. As applied to a vehicle (1) having an internal combustion engine, the analyzer includes: (i) a source of electromagnetic radiation (14, 16); and (ii) a sampling cell (12) which collects emission gases of interest and which is capable of withstanding hostile environments while preserving a "clear" optical path between the sensor sampling cell and the source of radiation. The analyzer further includes: (iii) a solid state sensor (24, 26, 28, 30, 32 ) of monolithic construction which selectively detects electromagnetic radiation that is absorbed or emitted by one or more chemical species of interest, that compensates for temporal and spatial variations in illumination level provided by the source, and that provides an electrical signal output, in either analog or digital format, that is related to the measured concentrations. The sensor includes, in combination, a plurality of highly sensitive electromagnetic radiation detectors (26), spectral filters (24) which may utilize multiple layers of deposited dielectric thin films and/or selectively absorbing layers, and low noise electronics which performs a variety of functions including amplification (28), multiplexing (30), analog to digital (A/D) conversion (33), signal processing (32), and input/output (I/O). In a presently preferred embodiment each radiation detector is a thermopile detector that is integrated upon a common substrate with the support electronics and an associated optical bandpass filter.
Inventors
- 👤 Michael D. Jack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:49
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0011; G01N33/0027; G01N33/0031; G01N33/0036; G01N33/0037; G01N33/004; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 53
Claim 1
Independent Claim
190 words
A vehicle that generates a gas comprised of a plurality of different chemical species, the vehicle comprising: means for sampling at least a portion of the gas, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means comprising an integral input filter for passing wavelengths within a band of wavelengths and being responsive to the band of wavelengths, that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species, for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the gas within said sampling means, wherein individual ones of said input filters are deposited upon a radiation receiving surface of an associated one of said radiation detector devices.
Claim 2
Dependent Claim
190 words
A vehicle that generates a gas comprised of a plurality of different chemical species, the vehicle comprising: means for sampling at least a portion of the gas, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means comprising an integral input filter for passing wavelengths within a band of wavelengths and being responsive to the band of wavelengths, that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species, for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the gas within said sampling means, wherein individual ones of said input filters are deposited upon a radiation receiving surface of an associated one of said radiation detector devices.
Claim 3
Dependent Claim
42 words
A vehicle as set forth in claim 1 and further comprising processor means having an input coupled to an output of said plurality of radiation detector means for determining a concentration of the predetermined ones of the chemical species within the gas.
Claim 4
Dependent Claim
75 words
A vehicle as set forth in claim 1 wherein individual ones of said radiation detector means are comprised of a radiation detector device that is fabricated within or upon a surface of a substrate, and further comprising a plurality of amplifier circuits individual ones of which have an input coupled to an output of one of said radiation detector devices, said plurality of amplifier circuits being fabricated within or upon the surface of said substrate.
Claim 5
Dependent Claim
35 words
A vehicle as set forth in claim 1 wherein individual ones of said integral input filters is comprised of a multi-layered filter that is deposited upon said radiation receiving surface of said radiation detector device.
Claim 6
Dependent Claim
34 words
A vehicle as set forth in claim 3 wherein individual ones of said radiation detector means are further comprised of a selectively absorbing film deposited upon a radiation receiving surface of said detector device.
Claim 7
Dependent Claim
34 words
A vehicle as set forth in claim 1 wherein individual ones of said radiation detector means are comprised of a thermopile radiation detector that is fabricated within or upon a surface of a substrate.
Claim 8
Dependent Claim
47 words
A vehicle as set forth in claim 1 wherein said optical source generates electromagnetic radiation having wavelengths within a least one spectral band selected from the group consisting of the ultraviolet spectral band, the visible spectral band, the infrared spectral band, and the far infrared spectral band.
Claim 9
Dependent Claim
26 words
A vehicle as set forth in claim 1 and further comprising means, coupled to said output port, for diffusing electromagnetic radiation passing through said output port.
Claim 10
Dependent Claim
43 words
A vehicle as set forth in claim 1 wherein said sampling means is comprised of a sampling cell having at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species.
Claim 11
Dependent Claim
24 words
A vehicle as set forth in claim 9 and further comprising means for retarding an accumulation of an emission gas constituent upon said window.
Claim 12
Dependent Claim
26 words
A vehicle as set forth in claim 1 wherein said sampling means has a plurality of apertures for forming said input port and said output port.
Claim 13
Dependent Claim
27 words
A vehicle as set forth in claim 1 wherein said optical source and at least said plurality of radiation detector means are located within said sampling means.
Claim 14
Dependent Claim
204 words
A vehicle that generates a gas comprised of a plurality of different chemical species, the vehicle comprising: means for sampling at least a portion of the gas, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the gas within said sampling means; wherein said sampling means is comprised of a sampling cell having at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and further comprising means for removing an accumulation of an emission gas constituent from said window.
Claim 15
Dependent Claim
204 words
A vehicle that generates a gas comprised of a plurality of different chemical species, the vehicle comprising: means for sampling at least a portion of the gas, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the gas within said sampling means; wherein said sampling means is comprised of a sampling cell having at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and further comprising means for removing an accumulation of an emission gas constituent from said window.
Claim 16
Dependent Claim
262 words
A spectroscopic system, comprising: means for sampling a gas or a liquid that is comprised of a plurality of different chemical species, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the sample within said sampling means, wherein individual ones of said radiation detector means are comprised of a radiation detector device that is fabricated within or upon a surface of a common substrate, and further comprising a plurality of amplifier circuits individual ones of which have an input coupled to an output of one of said radiation detector devices, said plurality of amplifier circuits also being fabricated within or upon the surface of said common substrate; and wherein individual ones of said radiation detector means are further comprised of an input filter for passing wavelengths within the band of wavelengths, said input filter being a multi-layered filter that is deposited upon a radiation receiving surface of said radiation detector device.
Claim 17
Dependent Claim
262 words
A spectroscopic system, comprising: means for sampling a gas or a liquid that is comprised of a plurality of different chemical species, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the sample within said sampling means, wherein individual ones of said radiation detector means are comprised of a radiation detector device that is fabricated within or upon a surface of a common substrate, and further comprising a plurality of amplifier circuits individual ones of which have an input coupled to an output of one of said radiation detector devices, said plurality of amplifier circuits also being fabricated within or upon the surface of said common substrate; and wherein individual ones of said radiation detector means are further comprised of an input filter for passing wavelengths within the band of wavelengths, said input filter being a multi-layered filter that is deposited upon a radiation receiving surface of said radiation detector device.
Claim 18
Dependent Claim
36 words
A spectrographic system as set forth in claim 14 wherein individual ones of said radiation detector means are comprised of a thermopile radiation detector that is fabricated within or upon a surface of the common substrate.
Claim 19
Dependent Claim
105 words
A spectrographic system as set forth in claim 14 and further comprising: a multiplexer circuit having a plurality of inputs individual ones of which are coupled to an output of one of said amplifier circuits; an analog to digital converter having an input coupled to an output of said multiplexer circuit; and processor means having an input coupled to an output of said analog to digital converter for determining a concentration of the predetermined ones of the chemical species within the sample, wherein at least said multiplexer circuit and said analog to digital converter are fabricated within or upon the surface of the common substrate.
Claim 20
Dependent Claim
48 words
A spectrographic system as set forth in claim 14 wherein said optical source generates electromagnetic radiation having wavelengths within a least one spectral band selected from the group consisting of the ultraviolet spectral band, the visible spectral band, the infrared spectral band, and the far infrared spectral band.
Claim 21
Dependent Claim
29 words
A spectrographic system as set forth in claim 14 and further comprising means, coupled to said output port, for diffusing the electromagnetic radiation that passes through said output port.
Claim 22
Dependent Claim
38 words
A spectrographic system as set forth in claim 14 wherein said sampling means includes at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species.
Claim 23
Dependent Claim
31 words
A spectrographic system as set forth in claim 19 and further comprising means for retarding an accumulation of a constituent of said gas or liquid upon said at least one window.
Claim 24
Dependent Claim
269 words
A spectrographic system comprising: means for sampling a gas or a liquid that is comprised of a plurality of different chemical species, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the sample within said sampling means, wherein individual ones of said radiation detector means are comprised of a radiation detector device that is fabricated within or upon a surface of a common substrate, and further comprising a plurality of amplifier circuits individual ones of which have an input coupled to an output of one of said radiation detector devices, said plurality of amplifier circuits also being fabricated within or upon the surface of said common substrate; wherein said sampling means includes at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and further comprising means for removing an accumulation of a constituent of said gas or liquid from said at least one window.
Claim 25
Dependent Claim
269 words
A spectrographic system comprising: means for sampling a gas or a liquid that is comprised of a plurality of different chemical species, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the sample within said sampling means, wherein individual ones of said radiation detector means are comprised of a radiation detector device that is fabricated within or upon a surface of a common substrate, and further comprising a plurality of amplifier circuits individual ones of which have an input coupled to an output of one of said radiation detector devices, said plurality of amplifier circuits also being fabricated within or upon the surface of said common substrate; wherein said sampling means includes at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and further comprising means for removing an accumulation of a constituent of said gas or liquid from said at least one window.
Claim 26
Dependent Claim
184 words
An electronic component for use in detecting a concentration of individual ones of a plurality of chemical species, comprising: an optical input port; a substrate; a plurality of radiation detector means individual ones of which have an input coupled to said optical input port, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species, individual ones of said radiation detector means being comprised of a radiation detector device that is fabricated within or upon a surface of the substrate; and a plurality of amplifier circuits individual ones of which have an input coupled to an output of one of said radiation detector devices, said plurality of amplifier circuits also being fabricated within or upon the surface of said substrate; wherein individual ones of said radiation detector means are further comprised of an input filter for passing wavelengths within the band of wavelengths, said input filter being a multi-layered filter that is deposited upon a radiation receiving surface of said radiation detector device.
Claim 27
Dependent Claim
184 words
An electronic component for use in detecting a concentration of individual ones of a plurality of chemical species, comprising: an optical input port; a substrate; a plurality of radiation detector means individual ones of which have an input coupled to said optical input port, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species, individual ones of said radiation detector means being comprised of a radiation detector device that is fabricated within or upon a surface of the substrate; and a plurality of amplifier circuits individual ones of which have an input coupled to an output of one of said radiation detector devices, said plurality of amplifier circuits also being fabricated within or upon the surface of said substrate; wherein individual ones of said radiation detector means are further comprised of an input filter for passing wavelengths within the band of wavelengths, said input filter being a multi-layered filter that is deposited upon a radiation receiving surface of said radiation detector device.
Claim 28
Dependent Claim
30 words
An electronic component as set forth in claim 22 wherein individual ones of said radiation detector means are further comprised of a selectively absorbing film for absorbing incident electromagnetic radiation.
Claim 29
Dependent Claim
35 words
An electronic component as set forth in claim 22 wherein individual ones of said radiation detector means are comprised of a thermopile radiation detector that is fabricated within or upon a surface of the substrate.
Claim 30
Dependent Claim
104 words
An electronic component as set forth in claim 22 and further comprising: a multiplexer circuit having a plurality of inputs individual ones of which are coupled to an output of one of said amplifier circuits; an analog to digital converter having an input coupled to an output of said multiplexer circuit; and processor means having an input coupled to an output of said analog to digital converter for determining a concentration of the predetermined ones of the chemical species within a sample, wherein at least said multiplexer circuit and said analog to digital converter are fabricated within or upon the surface of the substrate.
Claim 31
Dependent Claim
52 words
An electronic component as set forth in claim 22 wherein individual ones of said radiation detector means are responsive to electromagnetic radiation having wavelengths within a spectral band selected from the group consisting of the ultraviolet spectral band, the visible spectral band, the infrared spectral band, and the far infrared spectral band.
Claim 32
Dependent Claim
28 words
An electronic component as set forth in claim 22 wherein at least one of said radiation detector means is responsive to electromagnetic radiation that is absorbed by CO.
Claim 33
Dependent Claim
28 words
An electronic component as set forth in claim 22 wherein at least one of said radiation detector means is responsive to electromagnetic radiation that is absorbed by hydrocarbons.
Claim 34
Dependent Claim
30 words
An electronic component as set forth in claim 22 wherein at least one of said radiation detector means is responsive to electromagnetic radiation that is absorbed by CO 2 .
Claim 35
Dependent Claim
28 words
An electronic component as set forth in claim 22 wherein at least one of said radiation detector means is responsive to electromagnetic radiation that is absorbed by NO.
Claim 36
Dependent Claim
30 words
An electronic component as set forth in claim 22 wherein at least one of said radiation detector means is responsive to electromagnetic radiation that is absorbed by H 2 O.
Claim 37
Dependent Claim
36 words
An electronic component as set forth in claim 22 wherein at least one of said radiation detector means is responsive to electromagnetic radiation that is not strongly absorbed by any of the plurality of chemical species.
Claim 38
Dependent Claim
60 words
An electronic component as set forth in claim 22 and further comprising a plurality of input/output terminals, at least one of said terminals being coupled to means for providing a data output from said electronic component, the data output being expressive of an amount of electromagnetic radiation that is detected by individual ones of said plurality of radiation detector means.
Claim 39
Dependent Claim
214 words
A multispectral sensor system for sensing one or more different chemical species within a flow, comprising: means for sampling at least a portion of the flow, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a monolithic sensor assembly comprised of a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the sampled portion of the flow; wherein individual ones of said radiation detector means are fabricated upon or within a surface of a common substrate and are comprised of a radiation detector device having an integral input filter for passing wavelengths within the band of wavelengths, said integral input filter being deposited upon a radiation receiving surface of said radiation detector device.
Claim 40
Dependent Claim
214 words
A multispectral sensor system for sensing one or more different chemical species within a flow, comprising: means for sampling at least a portion of the flow, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a monolithic sensor assembly comprised of a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the sampled portion of the flow; wherein individual ones of said radiation detector means are fabricated upon or within a surface of a common substrate and are comprised of a radiation detector device having an integral input filter for passing wavelengths within the band of wavelengths, said integral input filter being deposited upon a radiation receiving surface of said radiation detector device.
Claim 41
Dependent Claim
39 words
A sensor system as set forth in claim 34 and further comprising processor means having an input coupled to an output of said plurality of radiation detector means for determining a concentration of predetermined ones of the chemical species.
Claim 42
Dependent Claim
51 words
A sensor system as set forth in claim 34, and further comprising a plurality of amplifier circuits individual ones of which have an input coupled to an output of one of said radiation detector devices, said plurality of amplifier circuits being fabricated within or upon the surface of said common substrate.
Claim 43
Dependent Claim
34 words
A sensor system as set forth in claim 34 wherein individual ones of said integral input filters are a multi-layered filter that is deposited upon said radiation receiving surface of said radiation detector device.
Claim 44
Dependent Claim
27 words
A sensor system as set forth in claim 34 wherein individual ones of said radiation detector means are further comprised of a multilayer selectively absorbing dark film.
Claim 45
Dependent Claim
36 words
A sensor system as set forth in claim 34 wherein individual ones of said radiation detector means are comprised of a thermopile radiation detector that is fabricated within or upon a surface of said common substrate.
Claim 46
Dependent Claim
48 words
A sensor system as set forth in claim 34 wherein said optical source generates electromagnetic radiation having wavelengths within a least one spectral band selected from the group consisting of the ultraviolet spectral band, the visible spectral band, the infrared spectral band, and the far infrared spectral band.
Claim 47
Dependent Claim
28 words
A sensor system as set forth in claim 34 and further comprising means, coupled to said output port, for diffusing electromagnetic radiation that passes through said output port.
Claim 48
Dependent Claim
44 words
A sensor system as set forth in claim 34 wherein said sampling means is comprised of a sampling cell having at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species.
Claim 49
Dependent Claim
24 words
A sensor system as set forth in claim 42 and further comprising means for retarding an accumulation of a flow constituent upon said window.
Claim 50
Dependent Claim
27 words
A sensor system as set forth in claim 34 wherein said sampling means has a plurality of apertures for forming said input port and said output port.
Claim 51
Dependent Claim
28 words
A sensor system as set forth in claim 34 wherein said optical source and at least said plurality of radiation detector means are located within said sampling means.
Claim 52
Dependent Claim
208 words
A multispectral sensor system for sensing one or more different chemical species within a flow, comprising: means for sampling at least a portion of the flow, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a monolithic sensor assembly comprised of a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the sampled portion of the flow; wherein said sampling means is comprised of a sampling cell having at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and further comprising means for removing an accumulation of a flow constituent from said window.
Claim 53
Dependent Claim
208 words
A multispectral sensor system for sensing one or more different chemical species within a flow, comprising: means for sampling at least a portion of the flow, said sampling means having an optical input port and an optical output port; an optical source having an output coupled to said optical input port of said sampling means, said optical source generating electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and a monolithic sensor assembly comprised of a plurality of radiation detector means individual ones of which have an input coupled to said optical output port of said sampling means, individual ones of said radiation detector means being responsive to a band of wavelengths that includes wavelengths that are absorbed by at least one of the predetermined ones of the chemical species for determining an amount of the electromagnetic radiation, within the band of wavelengths, that is transmitted through the sampled portion of the flow; wherein said sampling means is comprised of a sampling cell having at least one window that is substantially transparent to the electromagnetic radiation having wavelengths that are absorbed by predetermined ones of the chemical species; and further comprising means for removing an accumulation of a flow constituent from said window.
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