US5384640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas sample chamber for use with a source of coherent radiation
Assignee: Gaztech Corp
•
Filing: 1993-01-19
•
Granted: 1995-01-24
•
Expires: 2013-01-19
Abstract
Abstract A gas sample chamber that is particularly advantageous for use with a semiconductor laser has the form of an elongated hollow tube with a specularly reflective inside surface, a semiconductor laser located at one end of the tube and a detector located at the opposite end of the tube. In one embodiment, apertures in the wall of the tube permit a gas to enter and leave the sample chamber by free diffusion. In another embodiment the gas flows into the hollow tube from a pressurized source through a port or is drawn through the tube by a suction pump. In other embodiments, the tube is partitioned into two successive sections by means of a window located within the tube. The window is transparent to radiation of two different wavelengths that coincide with the absorption bands of two different gases. The semiconductor laser is tuned to these wavelengths successively so that two gas components can be detected and measured simultaneously.
Inventors
- 👤 Jacob Y. Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:58
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/01; G01N21/03; G01N21/05; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/3504; G01N21/39
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
101 words
A gas sample chamber for use with a source of coherent radiation, comprising in combination: an elongated hollow tube having a first end and a second end and having an inside surface that is specularly reflective, and including means for permitting the gas sample to enter and leave the space within said elongated hollow tube; a semiconductor laser located at the first end of said elongated hollow tube and oriented to project radiation toward the second end; a detector located at the second end of said elongated hollow tube and occupying substantially the entire cross section of said elongated hollow tube.
Claim 2
Dependent Claim
101 words
A gas sample chamber for use with a source of coherent radiation, comprising in combination: an elongated hollow tube having a first end and a second end and having an inside surface that is specularly reflective, and including means for permitting the gas sample to enter and leave the space within said elongated hollow tube; a semiconductor laser located at the first end of said elongated hollow tube and oriented to project radiation toward the second end; a detector located at the second end of said elongated hollow tube and occupying substantially the entire cross section of said elongated hollow tube.
Claim 3
Dependent Claim
16 words
The gas sample chamber of claim 1 wherein said means includes at least two spaced apertures.
Claim 4
Dependent Claim
21 words
The gas sample chamber of claim 2 wherein said at least two spaced apertures are each covered by a semipermeable membrane.
Claim 5
Dependent Claim
39 words
The gas sample chamber of claim 3 wherein said semipermeable membrane prevents particles larger than 0.1 micron from entering said elongated hollow tube while not interfering with diffusion of a gas into and out of said elongated hollow tube.
Claim 6
Dependent Claim
33 words
The gas sample chamber of claim 2 further comprising heating means for warming said elongated hollow tube to prevent condensation of gases or vapors on the inside surface of said elongated hollow tube.
Claim 7
Dependent Claim
191 words
A gas sample chamber for use with a source of coherent radiation, comprising in combination: an elongated hollow tube having a first end and a second end and having an inside surface that is specularly reflective; semiconductor laser means located at the first end of said elongated hollow tube, oriented to project radiation toward the second end, and producing radiation having a first wavelength λ 1 and a second wavelength λ 2 ; a window located between the first end and the second end of said elongated hollow tube, forming a gastight seal with the inside surface of said elongated hollow tube so as to partition said elongated hollow tube into a first section and a second section isolated from said first section, said window substantially transparent to radiation of wavelengths λ 1 and λ 2 ; first means for permitting a first gas to enter and leave the first section and second means for permitting a second gas to enter and leave the second section; and, a detector located at the second end of said elongated hollow tube and occupying substantially the entire cross section of said elongated hollow tube.
Claim 8
Dependent Claim
191 words
A gas sample chamber for use with a source of coherent radiation, comprising in combination: an elongated hollow tube having a first end and a second end and having an inside surface that is specularly reflective; semiconductor laser means located at the first end of said elongated hollow tube, oriented to project radiation toward the second end, and producing radiation having a first wavelength λ 1 and a second wavelength λ 2 ; a window located between the first end and the second end of said elongated hollow tube, forming a gastight seal with the inside surface of said elongated hollow tube so as to partition said elongated hollow tube into a first section and a second section isolated from said first section, said window substantially transparent to radiation of wavelengths λ 1 and λ 2 ; first means for permitting a first gas to enter and leave the first section and second means for permitting a second gas to enter and leave the second section; and, a detector located at the second end of said elongated hollow tube and occupying substantially the entire cross section of said elongated hollow tube.
Claim 9
Dependent Claim
17 words
The gas sample chamber of claim 6 wherein said first means include at least two spaced ports.
Claim 10
Dependent Claim
17 words
The gas sample chamber of claim 6 wherein said second means include at least two spaced ports.
Claim 11
Dependent Claim
17 words
The gas sample chamber of claim 6 wherein said first means includes at least two spaced apertures.
Claim 12
Dependent Claim
21 words
The gas sample chamber of claim 9 wherein said at least two spaced apertures are each covered by a semipermeable membrane.
Claim 13
Dependent Claim
40 words
The gas sample chamber of claim 10 wherein said semipermeable membrane prevents particles larger than 0.1 micron from entering said elongated hollow tube while not interfering with diffusion of said first gas into and out of said elongated hollow tube.
Claim 14
Dependent Claim
17 words
The gas sample chamber of claim 6 wherein said second means include at least two spaced apertures.
Claim 15
Dependent Claim
21 words
The gas sample chamber of claim 12 wherein said at least two spaced apertures are each covered by a semipermeable membrane.
Claim 16
Dependent Claim
40 words
The gas sample chamber of claim 13 wherein said semipermeable membrane prevents particles larger than 0.1 micron from entering said elongated hollow tube while not interfering with diffusion of said second gas into and out of said elongated hollow tube.
Claim 17
Dependent Claim
33 words
The gas sample chamber of claim 6 further comprising heating means for warming said elongated hollow tube to prevent condensation of gases or vapors on the inside surface of said elongated hollow tube.
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) | 1998-01-23 | 1998-07-25 | 1999-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-23 | 2002-07-25 | 2003-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-23 | 2006-07-25 | 2007-01-24 | $7700.00 | Window Closed / Lapsed |