US3895873A
Expired / Lapsed
US
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Spectroscopic analysis apparatus utilizing a tubular heating element and a passive sample holder
Assignee: THERMO JARRELL ASH Corp WALTHAM MA A CORP OF
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Filing: 1974-04-04
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Granted: 1975-07-22
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Expires: 1994-04-04
Abstract
Abstract Spectroscopic analysis apparatus utilizes a tubular electrothermal heating element and a passive sample holder. The sample holder is insertable through an access opening in the heating element to rest in intimate heat transfer contact with an interior surface, and includes a portion which restricts vapor flow through the access opening.
Inventors
- 👤 Allan G Dennison
- 👤 Martha F Bancroft
- 👤 Jr Stanley B Smith
- 👤 Marc Joshua Tolkoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:33
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/0014; G; G01; G01N; G01N21/00; G01N21/62; G01N21/71; G01N21/74
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
206 words
In a spectroscopic system for determining the quantity of a substance of interest in a sample material, said system including a radiation source for transmitting a radiation beam at a characteristic wavelength through a sample location, and a radiation detector for sensing said beam after transit through the sample location, sample excitation structure comprising: a tubular heating element positioned at said sample location, said heating element hAving a longitudinal axis aligned with said radiation beam, the ends of said heating element being transparent to said beam, an access opening in a longitudinal wall of said heating element, and a heating surface adjacent said access opening, a sample holder insertable into said heating element through said access opening, said sample holder including a sample receiving surface for receiving sample material and a heat transmitting surface that nests in intimate heat transfer contact with said heating surface of said heating element when the holder is inserted into said heating element, and structure for applying an energizing signal to said heating element of sufficient intensity to generate heat for conductive transmission from said heating surface through the nested heat transmitting surface of said sample holder to excite said sample material on said sample receiving surface to an atomic state.
Claim 2
Dependent Claim
206 words
In a spectroscopic system for determining the quantity of a substance of interest in a sample material, said system including a radiation source for transmitting a radiation beam at a characteristic wavelength through a sample location, and a radiation detector for sensing said beam after transit through the sample location, sample excitation structure comprising: a tubular heating element positioned at said sample location, said heating element hAving a longitudinal axis aligned with said radiation beam, the ends of said heating element being transparent to said beam, an access opening in a longitudinal wall of said heating element, and a heating surface adjacent said access opening, a sample holder insertable into said heating element through said access opening, said sample holder including a sample receiving surface for receiving sample material and a heat transmitting surface that nests in intimate heat transfer contact with said heating surface of said heating element when the holder is inserted into said heating element, and structure for applying an energizing signal to said heating element of sufficient intensity to generate heat for conductive transmission from said heating surface through the nested heat transmitting surface of said sample holder to excite said sample material on said sample receiving surface to an atomic state.
Claim 3
Dependent Claim
61 words
The apparatus of claim 1 and further including seal structure formed integrally with said sample holder, said seal structure being adapted to lodge in said access opening and occupy substantially the entire cross-section area thereof when said holder is inserted into said element, thereby restricting escape of sample material in the atomic state from said heating element through said access opening.
Claim 4
Dependent Claim
90 words
The apparatus of claim 1 wherein the bottom surface of said sample support wall and the bottom interior surface of said heating element are substantially flat, said access opening has a flat bottom wall formed co-extensively with the bottom interior surface of said heating element, thereby enabling said sample holder to be positioned within said heating element in intimate heat transfer contact therewith by being slid through said access opening with the bottom surface of said support wall in continuous contact with the bottom interior surface of said heating element.
Claim 5
Dependent Claim
62 words
The apparatus of claim 1 and further including a guide surface for said sample holder on the opposite longitudinal wall of said heating element from said access opening and aligned therewith, said sample holder being adapted to engage said guide surface during insertion into the heating element, to thereby aid in the positive positioning of said sample holder on said heating surface.
Claim 6
Dependent Claim
103 words
The apparatus of claim 1 wherein said energizing signal applying structure includes terminal structure at each end of said heating element, each said terminal structure comprising an inner member formed from an electrically conductive material, an outer member formed from an electrically conductive material of greater thermal resistance than said inner member, and an electrically conductive mounting support for said outer member, said inner member being in electrical contact with at least a substantial portion of the perimeter of said heating element, and said outer member being in electrical contact with at least a substantial portion of the perimeter of said inner member.
Claim 7
Dependent Claim
59 words
The apparatus of claim 1 and further including a thermally insulative housing enclosing said heating element, said housing including windows enabling the transmission of said radiation beam through said heating element, a pair of electrically conductive support structures mounting said element in said housing and wherein said energizing signal applying structure includes electrical conductors connected to said support structures.
Claim 8
Dependent Claim
175 words
Apparatus for heating a sample material to an atomic state suitable for spectroscopic analysis, comprising: a tubular heating element, at least the bottom wall of which is formed from an electrothermal material, said tubular element being transparent to a radiation beam transmitted along its longitudinal axis, an access opening in one longitudinal wall of said heating element, a sample holder insertable into said heating element through said access opening, said sample holder including a heat transmitting portion adapted to overlie the bottom heating element wall in intimate heat transfEr contact therewith, and a manipulating portion extending outwardly from said heat transmitting portion through said access opening when said heat transmitting portion is in intimate heat transfer contact with said bottom heating element wall, and means for transmitting an electrical energizing signal to heat the electrothermal material of said heating element, and thereby excite a sample material in said holder to an atomic state by heat conduction from the bottom wall of the heating element, through the said sample holder heat transmitting portion to the sample.
Claim 9
Dependent Claim
175 words
Apparatus for heating a sample material to an atomic state suitable for spectroscopic analysis, comprising: a tubular heating element, at least the bottom wall of which is formed from an electrothermal material, said tubular element being transparent to a radiation beam transmitted along its longitudinal axis, an access opening in one longitudinal wall of said heating element, a sample holder insertable into said heating element through said access opening, said sample holder including a heat transmitting portion adapted to overlie the bottom heating element wall in intimate heat transfEr contact therewith, and a manipulating portion extending outwardly from said heat transmitting portion through said access opening when said heat transmitting portion is in intimate heat transfer contact with said bottom heating element wall, and means for transmitting an electrical energizing signal to heat the electrothermal material of said heating element, and thereby excite a sample material in said holder to an atomic state by heat conduction from the bottom wall of the heating element, through the said sample holder heat transmitting portion to the sample.
Claim 10
Dependent Claim
16 words
The apparatus of claim 7 wherein the entire tubular heating element is formed of electrothermal material.
Claim 11
Dependent Claim
51 words
The apparatus of claim 8 wherein said heating element comprises a graphite tube and a thin layer of another material on the exterior surface of said graphite tube of sufficient thickness to reduce the thermal emissivity of said heating element to a level significantly less than the thermal emissivity of graphite.
Claim 12
Dependent Claim
75 words
The apparatus of claim 9 wherein said sample holder has a recess in its upper surface for holding a sample, said heat transmitting portion includes a planar portion below said recess, said heating element includes a bottom wall that has a planar interior surface, said access opening is formed in a side wall of said heating element, and the base of said access opening is aligned with said planar interior surface of said heating element.
Claim 13
Dependent Claim
71 words
The apparatus of claim 10 wherein said recess is formed in a forward portion of said sample holder, the front-to-rear dimension of said recess corresponding to the width between the side walls of said heating element, the rearward portion of said sample holder corresponding in cross-sectional dimension to said access opening so as to seal said access opening when said sample holder is inserted into said heating element through said opening.
Claim 14
Dependent Claim
33 words
The apparatus of claim 11 wherein said sample holder is formed from graphite, and the thickness of said heat transmitting portion and the walls of said heating element is less than one millimeter.
Claim 15
Dependent Claim
198 words
Spectroanalysis cell apparatus comprising a tubular member having a sample excitation region of uniform cross-sectional configuration along its length through which a radiation analysis beam may be passed, the top and bottom walls of said member being closed at said sample excitation region an access opening in the side wall of said member at said sample excitation region, and said member having a sample holder receiving surface aligned with said opening, terminal structure connected to said tubular member on opposite sides of said sample excitation region for supplying electrical current for flow through said member to provide I2R heating of said sample holder receiving surface, and a sample holder insertable into said sample through said access opening for positioning on said sample holder receiving surface, said sample holder having a surface that mates congruently in intimate heat transfer contact with said sample holder receiving surface, and a manipulating portion that extends outwardly from said tubular member when said sample holder is disposed on said sample holder receiving surface, heat from said sample holder receiving surface being transmitted by conduction to said mating sample holder to excite sample material on said sample holder to an atomic state for analysis.
Claim 16
Dependent Claim
198 words
Spectroanalysis cell apparatus comprising a tubular member having a sample excitation region of uniform cross-sectional configuration along its length through which a radiation analysis beam may be passed, the top and bottom walls of said member being closed at said sample excitation region an access opening in the side wall of said member at said sample excitation region, and said member having a sample holder receiving surface aligned with said opening, terminal structure connected to said tubular member on opposite sides of said sample excitation region for supplying electrical current for flow through said member to provide I2R heating of said sample holder receiving surface, and a sample holder insertable into said sample through said access opening for positioning on said sample holder receiving surface, said sample holder having a surface that mates congruently in intimate heat transfer contact with said sample holder receiving surface, and a manipulating portion that extends outwardly from said tubular member when said sample holder is disposed on said sample holder receiving surface, heat from said sample holder receiving surface being transmitted by conduction to said mating sample holder to excite sample material on said sample holder to an atomic state for analysis.
Claim 17
Dependent Claim
13 words
The apparatus of claim 13 wherein said sample holder receiving surface is planar.
Claim 18
Dependent Claim
22 words
The apparatus of claim 13 wherein each said terminal structure is in electrical contact with the entire perimeter of said tubular member.
Claim 19
Dependent Claim
55 words
The apparatus of claim 13 wherein said tubular member comprises a base tube of one material and a thin layer of another material on the external surface of said base tube, said this layer reducing the thermal emissivity of said tubular member to a level significantly less than the thermal emissivity of said base tube.
Claim 20
Dependent Claim
18 words
The apparatus of claim 16 wherein saId base tube is graphite and said thin layer is a metal.
Claim 21
Dependent Claim
50 words
The apparatus of claim 13 wherein said manipulating portion has dimensions corresponding to the dimensions of said access opening so that said manipulating portion restricts escape of excited sample material from said tubular member through said access opening when said sample holder is positioned on said sample holder receiving surface.
Claim 22
Dependent Claim
24 words
The apparatus of claim 13 wherein said sample holder includes a recess for receiving sample material, said recess being directly above said mating surface.
References Cited (Backward Citations)
US3824016A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |