US4350718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of fabricating graphite tube
Assignee: PE Manufacturing GmbH
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Filing: 1981-09-21
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Granted: 1982-09-21
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Expires: 2001-09-21
Abstract
Abstract A method for coating a graphite tube for use in atomic absorption spectroscopy includes forming a layer of an adhesive volatile material on the tube. An inert material, in the form of a powder, is applied to the layer and heated to pyrolyze the inert material. Thereafter, the graphite tube is coated with pyrolytic graphite.
Inventors
- 👤 Bernhard Huber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:40
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/52; C04B41/80; C04B41/81; C04B41/89; G; G01; G01N; G01N21/00; G01N21/62; G01N21/71; G01N21/74
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
52 words
Method of coating a graphite tube, said method comprising the steps of: forming a layer of adhesive, volatile material on said graphite tube; applying a powder of inert material to said layer; pyrolyzing, in the presence of an inert gas flow, said layer; and thereafter coating said graphite tube with pyrolytic graphite.
Claim 2
Dependent Claim
52 words
Method of coating a graphite tube, said method comprising the steps of: forming a layer of adhesive, volatile material on said graphite tube; applying a powder of inert material to said layer; pyrolyzing, in the presence of an inert gas flow, said layer; and thereafter coating said graphite tube with pyrolytic graphite.
Claim 3
Dependent Claim
13 words
Method as claimed in claim 1 wherein said adhesive, volatile layer includes beeswax.
Claim 4
Dependent Claim
20 words
Method as claimed in claim 2 wherein said applying step includes immersing said graphite tube in a solution of beeswax.
Claim 5
Dependent Claim
26 words
Method as claimed in claims 1, 2 or 3 further including the step of admixing a carbonaceous gas with said inert gas during said coating step.
Claim 6
Dependent Claim
37 words
Method as claimed in claim 4 wherein said graphite tube is heated to about 1900° C., said inert gas is argon and said carbonaceous gas is methane in an admixture of up to 10 percent by volume.
Claim 7
Dependent Claim
22 words
Method as claimed in claim 1 wherein said graphite tube is heated in a graphite tube atomizer of an atomic absorption spectrometer.
Claim 8
Dependent Claim
14 words
Method as claimed in claim 1 wherein said inert material is a high-melting carbide.
Claim 9
Dependent Claim
14 words
Method as claimed in claim 1 wherein said inert material is a ceramic material.
Claim 10
Dependent Claim
12 words
Method as claimed in claim 1 wherein said inert material is tungsten.
Claim 11
Dependent Claim
39 words
Method as claimed in claim 9 wherein said applying step includes introducing said graphite tube into a packing of carbide forming metal in powder form and heating said tube therein to the temperature whereat a superficial carbide is formed.
References Cited (Backward Citations)
US3860437A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-09-20 | 1986-03-22 | 1986-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-20 | 1990-03-22 | 1990-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-20 | 1994-03-22 | 1994-09-21 | $7700.00 | Window Closed / Lapsed |