US4239967A
Expired / Lapsed
US
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Trace water measurement
Assignee: International Business Machines Corp
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Filing: 1979-04-13
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Granted: 1980-12-16
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Expires: 1999-04-13
Abstract
Abstract A method for measuring trace amounts of water in an atmosphere. A dry inert gas is used as the carrier gas and a dry gas comprising about 20 percent oxygen and about 80 percent inert gas is used as the reagent gas. The ionization source is operated at atmospheric pressure. A small electric field of about 200 volts per centimeter is applied across the ion drift chamber and it is biased to repel negative ions to a quadrupole mass filter. Measurements at an m/e value of 52 are integrated over a period of time. The results of the integration, when compared to a calibration chart, indicate the amount of water that had been present in the atmosphere being measured.
Inventors
- 👤 Timothy W. Carr
- 👤 Edwin A. Corl
- 👤 Carl G. Majtenyi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:05
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/62; G01N27/622; G01N27/623
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
74 words
A method of measuring the amount of water in an atmosphere comprising the steps of: treating the atmosphere in such a manner as to produce a number of O(H 2 O) 2 - ions that is proportional to the amount of water in said atmosphere; measuring the amount of said ions contained in said atmosphere; and comparing said measurement to calibration data to obtain an indication of the amount of water in said atmosphere.
Claim 2
Independent Claim
74 words
A method of measuring the amount of water in an atmosphere comprising the steps of: treating the atmosphere in such a manner as to produce a number of O(H 2 O) 2 - ions that is proportional to the amount of water in said atmosphere; measuring the amount of said ions contained in said atmosphere; and comparing said measurement to calibration data to obtain an indication of the amount of water in said atmosphere.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said measuring step comprises measuring the m/e=52 peaks in signatures of said atmosphere.
Claim 4
Dependent Claim
51 words
The method of claim 1 wherein said measuring step comprises: measuring over a period of time, the m/e=52 peaks in signatures of said atmosphere; and integrating over said period of time, the latter measurements to obtain an indication of the amount of O(H 2 O) 2 - ions in said atmosphere.
Claim 5
Dependent Claim
28 words
The metod of claim 3 wherein said step of treating said atmosphere comprises: mixing said atmosphere with a reagent gas; and exposing said mixture to an ionization source.
Claim 6
Dependent Claim
28 words
The method of claim 4 wherein said reagent gas comprises oxygen and inert gases and said exposure takes place at a temperature in excess of approximately 200° C.
Claim 7
Dependent Claim
14 words
The method of claim 5 wherein said exposure takes place at approximately atmospheric pressure.
Claim 8
Dependent Claim
30 words
The method of claim 6 wherein: said reagent gas is zero grade air; said ionization source is a radioactive ionization source; and said exposure takes place at approximately 210° C.
Claim 9
Dependent Claim
54 words
The method of claim 1, 3, 6 or 7 further including the steps of deriving said calibration data by: subjecting atmospheres which contain known amounts of water to said treating and measuring steps; and gathering, as the calibration data, data which correlates the known amounts of water with the results of said measuring steps.
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) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |