US3777366A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chamber and filament method for flow through thermal conductivity micro size measuring chambers
Assignee: TRIANGLE ENVIRONMENT CORP
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Filing: 1972-06-21
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Granted: 1973-12-11
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Expires: 1992-06-21
Abstract
Abstract A chamber and filament method of chamber formation and filament support for micro size, i.e. 10 microliters or less, thermal conductivity measuring chambers is based on supporting the detecting filaments on a suitable relatively thin electrically and thermally insulating substrate, e.g. mica, and utilizing the wall support surface of the substrate as a significant portion of the total wall surface of the detecting chamber thereby mechanically stabilizing the filaments, minimizing the chamber size and dramatically increasing the ability of the chamber to detect the presence and concentration of minute quantities of unknowns, e.g. insecticide on a lettuce leaf.
Inventors
- 👤 M Kiefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:36
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/18; G01N27/185; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
228 words
The method of forming micro size chambers of ten microliters or less for a flow through thermal conductivity detector and of forming and mounting a detecting filament therein comprising: a. forming a mounting disc of thermally and electrically insulating material to provide on one side thereof a substantially rigid wall surface filament mounting area located within a surrounding surface area suited to forming a detecting chamber and on the opposite side of said disc providing a substantially flat clamping surface; b. forming on said mounting disc within said mounting area a filament constituting a physically and electrically precision formed thin electrically conducting strip adhered for its entire length to said wall surface area; c. mounting said mounting disc between additional structural means adapted to engage and clamp both sides of said disc and to provide a structural configuration mating with said disc mounting and surrounding areas to form a detecting chamber in which the said mounting area constitutes a portion of the wall area of said chamber and acts as a reflecting barrier for gases admitted thereto and in such manner that said chamber is hermetically sealed from external gases and is communicated with appropriate inlet and outlet passageways for entry of selected gases to said chamber; and d. electrically connecting said filament to an external detecting circuit and said passageways to external gas inlet and outlet means.
Claim 2
Independent Claim
228 words
The method of forming micro size chambers of ten microliters or less for a flow through thermal conductivity detector and of forming and mounting a detecting filament therein comprising: a. forming a mounting disc of thermally and electrically insulating material to provide on one side thereof a substantially rigid wall surface filament mounting area located within a surrounding surface area suited to forming a detecting chamber and on the opposite side of said disc providing a substantially flat clamping surface; b. forming on said mounting disc within said mounting area a filament constituting a physically and electrically precision formed thin electrically conducting strip adhered for its entire length to said wall surface area; c. mounting said mounting disc between additional structural means adapted to engage and clamp both sides of said disc and to provide a structural configuration mating with said disc mounting and surrounding areas to form a detecting chamber in which the said mounting area constitutes a portion of the wall area of said chamber and acts as a reflecting barrier for gases admitted thereto and in such manner that said chamber is hermetically sealed from external gases and is communicated with appropriate inlet and outlet passageways for entry of selected gases to said chamber; and d. electrically connecting said filament to an external detecting circuit and said passageways to external gas inlet and outlet means.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein said mounting disc is formed as a thermally and electrically insulating coating adhered to a surface of said structural means.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein said structural means includes additional disc means providing a void, said void being mated with said mounting area to form said chamber.
Claim 5
Dependent Claim
23 words
The method of claim 2 wherein said mounting disc provides a cavity containing said mounting area and forming said chamber with said cavity.
Claim 6
Dependent Claim
25 words
The method of claim 2 wherein said structural means provides a cavity mating with said mounting area and using said cavity to form said chamber.
Claim 7
Dependent Claim
26 words
The method of claim 1 wherein said filament is initially formed of sputtered metal and said sputtered metal is thereafter annealed to achieve improved electrical stability.
Claim 8
Dependent Claim
10 words
The method of claim 6 wherein said metal is nickel.
Claim 9
Dependent Claim
26 words
The method of claim 2 wherein said filament is initially formed of sputtered metal and said sputtered metal is thereafter annealed to achieve improved electrical stability.
Claim 10
Dependent Claim
26 words
The method of claim 3 wherein said filament is initially formed of sputtered metal and said sputtered metal is tHereafter annealed to achieve improved electrical stability.
Claim 11
Dependent Claim
23 words
The method of claim 8 wherein said mounting disc provides a cavity containing said mounting area and forming said chamber with said cavity.
Claim 12
Dependent Claim
25 words
The method of claim 8 wherein said structural means provides a cavity mating with said mounting area and using said cavity to form said chamber.
References Cited (Backward Citations)
US2821462A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |