US4640627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for monitoring a plasma torch
Assignee: PerkinElmer Instruments LLC
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Filing: 1983-08-26
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Granted: 1987-02-03
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Expires: 2003-08-26
Abstract
Abstract An apparatus for monitoring a plasma torch includes a dedicated photometer which produces a signal representative of the temperature of a quartz tube of the torch, which signal can be used to reduce the temperature thereof.
Inventors
- 👤 David H. Tracy
- 👤 Michael J. O'Brien
- 👤 Walter Bohler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:44
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/02; G01J5/04; G01J5/041; G01J5/0014; G01J5/0018; G01J5/08; G01J5/0801; G01J5/0803; G01J5/0805; G01J5/0893; G01J5/10; G01J5/34; H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/30; H05H1/32; H05H1/34; H05H1/36; G01N; G01N21/00; G01N21/62; G01N21/71; G01N21/73
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
119 words
An apparatus for monitoring the temperature of a quartz tube used to partially surround a plasma flame issuing therefrom comprising; in combination: electro-optical detector means remote from said quartz tube for producing an electrical signal whose amplitude is a function of the temperature of the quartz tube, said electro-optical detector means being disposed to receive infrared radiation from at least part of the exterior surface of the quartz tube and at least part of the interior surface of the tube; and threshold means responsive to said electrical signal being above an upper threshold level indicative of a temperature approaching the melting point of quartz to produce a signal to turn off the plasma flame issuing from the quartz tube.
Claim 2
Independent Claim
119 words
An apparatus for monitoring the temperature of a quartz tube used to partially surround a plasma flame issuing therefrom comprising; in combination: electro-optical detector means remote from said quartz tube for producing an electrical signal whose amplitude is a function of the temperature of the quartz tube, said electro-optical detector means being disposed to receive infrared radiation from at least part of the exterior surface of the quartz tube and at least part of the interior surface of the tube; and threshold means responsive to said electrical signal being above an upper threshold level indicative of a temperature approaching the melting point of quartz to produce a signal to turn off the plasma flame issuing from the quartz tube.
Claim 3
Dependent Claim
27 words
Apparatus as claimed in claim 1 wherein said detector means includes a filter element selected to pass wavelengths from between about 8 mm to about 15 mm.
Claim 4
Dependent Claim
26 words
Apparatus as claimed in claim 1 wherein said detector means includes a photometer having an entrance aperture aligned to receive the infrared radiation from the tube.
Claim 5
Dependent Claim
25 words
Apparatus as claimed in claim 3 wherein said photometer further includes: an aperture stop, said aperture stop being located between said lens and said detector.
Claim 6
Dependent Claim
27 words
Apparatus as claimed in claim 4 wherein said detector means includes a filter element selected to pass wavelengths from between about 8 mm to about 15 mm.
Claim 7
Dependent Claim
27 words
Apparatus as claimed in claim 3 wherein said detector means includes a filter element selected to pass wavelengths from between about 8 mm to about 15 mm.
Claim 8
Dependent Claim
37 words
Apparatus as claimed in claim 1 wherein said threshold means includes means to detect when the temperature of the tube is below a second threshold less than said upper threshold and to eliminate said turn off signal.
Claim 9
Dependent Claim
27 words
Apparatus as claimed in claim 7 wherein said detector means includes a filter element selected to pass wavelengths from between about 8 mm to about 15 mm.
Claim 10
Dependent Claim
28 words
Apparatus as claimed in claim 1 additionally including a chopper disposed between said detector means and the tube to modulate the infrared radiation impinging on said detector means.
Claim 11
Dependent Claim
27 words
Apparatus as claimed in claim 9 wherein said detector means includes a filter element selected to pass wavelengths from between about 8 mm to about 15 mm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-02 | 1990-08-04 | 1991-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-02 | 1994-08-04 | 1995-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-02 | 1998-08-04 | 1999-02-03 | $7700.00 | Window Closed / Lapsed |