US4374090A
Expired / Lapsed
US
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Chemical bias agent detection
Assignee: Brunswick Corp
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Filing: 1981-07-06
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Granted: 1983-02-15
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Expires: 2001-07-06
Abstract
Abstract The present invention is directed to an ionization cell for detecting the presence of very minute concentrations of certain chemical agents. The effective sensitivity of conventional chemical agent detectors is restricted in the presence of certain interferants such as jet fuel, gasoline, smoke, turpentine and the like. Herein a "chemical bias," that is a background concentration of a simulant is provided at the inlet of an ionization detector, which chemical bias is effective by charge exchange to prevent the interferants from dominating the signal.
Inventors
- 👤 B. Thompson McClure
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:31
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/62; G01N27/64; G01N27/66; G01N27/68; G01N27/70
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
An ionization type chemical agent detector with a chemical bias comprising: a housing having an inlet and an outlet for passage of gas samples; means defining a source of a chemical bias agent selected from the group consisting of dimethylmethyl phosphonate, dissopropylmethyl phosphonate, di-N-butylamine, tributylamine and dimethyl sulfoxide connected to the housing to add said bias chemical to the incoming gas samples; means defining a source of ionization mounted in the housing to ionize said incoming gas samples; means defining an attrition region in said housing downstream from said source of ionization; and a collector electrode mounted near said housing outlet for generating an electric signal which is a function of ions present in the gas sample after passing through said attrition region.
Claim 2
Dependent Claim
123 words
An ionization type chemical agent detector with a chemical bias comprising: a housing having an inlet and an outlet for passage of gas samples; means defining a source of a chemical bias agent selected from the group consisting of dimethylmethyl phosphonate, dissopropylmethyl phosphonate, di-N-butylamine, tributylamine and dimethyl sulfoxide connected to the housing to add said bias chemical to the incoming gas samples; means defining a source of ionization mounted in the housing to ionize said incoming gas samples; means defining an attrition region in said housing downstream from said source of ionization; and a collector electrode mounted near said housing outlet for generating an electric signal which is a function of ions present in the gas sample after passing through said attrition region.
Claim 3
Dependent Claim
14 words
The detector according to claim 1 in which the bias chemical is dimethylmethyl phosphonate.
Claim 4
Dependent Claim
13 words
The detector according to claim 1 in which the bias chemical is tributylamine.
Claim 5
Dependent Claim
55 words
The detector according to claim 1 in which said bias chemical yields ultimate charged species (ions) which have higher ionization potentials and lower masses than the ultimate ion species which result when an agent to be detected is present and which bias chemical has a lower ionization potential and a higher mass than the interferants.
Claim 6
Dependent Claim
25 words
The detector according to claim 1 in which said bias chemical has a lower electron affinity and a lower mass than the agent being detected.
References Cited (Backward Citations)
US3540851A
Cited
US3835328A
Cited
US4148612A
Cited
US4075550A
Cited
US4150951A
Cited
US4203726A
Cited
US4309187A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-14 | 1986-08-16 | 1987-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-14 | 1990-08-16 | 1991-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-14 | 1994-08-16 | 1995-02-15 | $7700.00 | Window Closed / Lapsed |