Patent US3992153A successfully refreshed from Google Patents.
US3992153A
Expired / Lapsed
US
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Dosimeter for oxides of nitrogen
Assignee: United States Department of the Interior
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Filing: 1976-05-20
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Granted: 1976-11-16
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Expires: 1996-05-20
Abstract
Abstract A dosimeter for the determination of integrated exposures to NO, NO2 or exposures to both gases. The dosimeter provides for a convenient and accurate method for the determination of exposures which may be encountered by workers or miners in field environments.
Inventors
- 👤 Benjamin I. Ferber
- 👤 Fredrick A. Sharp
- 👤 Robert W. Freedman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:41
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0011; G01N33/0013; Y; Y10; Y10S; Y10S436/00; Y10S436/902; Y10T; Y10T436/00; Y10T436/17; Y10T436/177692; Y10T436/178459; Y10T436/179228
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
43 words
A dosimeter for the detection of NO 2 gas comprising a container, open to the atmosphere only by means of a membrane which is substantially permeable only to gases, having therein an aqueous solution which converts NO 2 to NO 3 - ion.
Claim 2
Dependent Claim
43 words
A dosimeter for the detection of NO 2 gas comprising a container, open to the atmosphere only by means of a membrane which is substantially permeable only to gases, having therein an aqueous solution which converts NO 2 to NO 3 - ion.
Claim 3
Dependent Claim
13 words
The dosimeter of claim 1, wherein said membrane is a dimethyl silicone membrane.
Claim 4
Dependent Claim
19 words
The dosimeter of claim 1, wherein said dosimeter holds about 2 to about 4 milliliters of said aqueous solution.
Claim 5
Dependent Claim
13 words
The dosimeter of claim 1, wherein said membrane is about 1 mil thick.
Claim 6
Dependent Claim
16 words
The dosimeter of claim 1, further comprising a means to attach said dosimeter to a wearer.
Claim 7
Dependent Claim
41 words
The dosimeter of claim 1, further comprising a converting means situated on the side of said membrane opposite from said aqueous solution for converting NO to NO 2 by which said dosimeter can detect levels of NO and NO 2 .
Claim 8
Dependent Claim
20 words
The dosimeter of claim 6, wherein said converting means is a filter of an inert support material containing sodium dichromate.
Claim 9
Dependent Claim
26 words
The dosimeter of claim 1, wherein said aqueous solution comprises sulfuric acid, water and an oxidation agent which converts NO 2 to NO 3 - ion.
Claim 10
Dependent Claim
12 words
The dosimeter of claim 8, wherein said oxidation agent is hydrogen peroxide.
Claim 11
Dependent Claim
31 words
The dosimeter of claim 8, wherein said aqueous solution is about 0.0005 molar in sulfuric acid and said oxidation agent is hydrogen peroxide present in an amount of about 0.004 molar.
Claim 12
Independent Claim
110 words
A method for the determination of exposure to nitrogen dioxide gas in an atmosphere comprising the steps of: a. exposing to an atmosphere, a dosimeter comprising a container, open to the atmosphere by means of a membrane which is substantially permeable only to gases, having therein an aqueous solution which converts NO 2 to NO 3 - ion; b. determining the concentration of NO 3 - ion in solution; and c. determining the concentration of NO 2 in said atmosphere by correlation of said concentration of NO 3 - with other concentrations of NO 3 - ions found when said dosimeter was exposed to known concentrations of NO 2 gas.
Claim 13
Independent Claim
110 words
A method for the determination of exposure to nitrogen dioxide gas in an atmosphere comprising the steps of: a. exposing to an atmosphere, a dosimeter comprising a container, open to the atmosphere by means of a membrane which is substantially permeable only to gases, having therein an aqueous solution which converts NO 2 to NO 3 - ion; b. determining the concentration of NO 3 - ion in solution; and c. determining the concentration of NO 2 in said atmosphere by correlation of said concentration of NO 3 - with other concentrations of NO 3 - ions found when said dosimeter was exposed to known concentrations of NO 2 gas.
Claim 14
Dependent Claim
24 words
The method of claim 11, wherein said aqeuous solution is present in said dosimeter in an amount of about 2 to about 4 milliliters.
Claim 15
Dependent Claim
30 words
The method of claim 11, wherein said exposing step (a) is performed by the wearing of said dosimeter by a worker in an atmosphere suspected of containing NO 2 gas.
Claim 16
Dependent Claim
31 words
The method of claim 11, wherein said aqueous solution is about 0.0005 molar in sulfuric acid and said oxidation agent is hydrogen peroxide present in an amount of about 0.004 molar.
Claim 17
Dependent Claim
22 words
The method of claim 11, wherein said exposing step (a) is performed at a temperature of from about 15° to 50° C.
Claim 18
Dependent Claim
24 words
The method of claim 11, wherein the concentration of NO 2 gas is said atmosphere is from about 1.2 to 10 parts per million.
Claim 19
Dependent Claim
20 words
The method of claim 11, wherein chloride ion is removed from said aqueous solution after step (a) and before (b).
Claim 20
Dependent Claim
19 words
The method of claim 17, wherein said chloride ion is removed by the precipitation of an insoluble chlorine compound.
Claim 21
Dependent Claim
13 words
The method of claim 18, wherein said insoluble chlorine compound is silver chloride.
Claim 22
Independent Claim
143 words
A method for the determination of exposure to NO and NO 2 gases in an atmosphere comprising the steps of: a. exposing to an atmosphere, a dosimeter comprising a sealed container, open to the atmosphere by means of a membrane which is substantially permeable only to gases, having therein an aqueous solution which converts NO 2 to NO 3 - ion and which contains a converting means, situated on the side of said membrane opposite from said aqueous solution, for converting NO to NO 2 ; b. determining the concentration of NO 3 - ion in said solution; and c. determining the concentraton of NO and NO 2 in said atmosphere by correlation of said concentration of NO 3 - with other concentrations of NO 3 - ion found when said dosimeter was exposed to known concentrations of NO and NO 2 .
Claim 23
Independent Claim
143 words
A method for the determination of exposure to NO and NO 2 gases in an atmosphere comprising the steps of: a. exposing to an atmosphere, a dosimeter comprising a sealed container, open to the atmosphere by means of a membrane which is substantially permeable only to gases, having therein an aqueous solution which converts NO 2 to NO 3 - ion and which contains a converting means, situated on the side of said membrane opposite from said aqueous solution, for converting NO to NO 2 ; b. determining the concentration of NO 3 - ion in said solution; and c. determining the concentraton of NO and NO 2 in said atmosphere by correlation of said concentration of NO 3 - with other concentrations of NO 3 - ion found when said dosimeter was exposed to known concentrations of NO and NO 2 .
Claim 24
Dependent Claim
25 words
The method of claim 20, wherein said aqueous solution is present in said dosimeter in an amount of from about 2 to about 4 milliliters.
Claim 25
Dependent Claim
32 words
The method of claim 20, wherein said exposing step (a) is performed by the wearing of said dosimeter by a worker in an atmosphere suspected of containing NO and NO 2 gases.
Claim 26
Dependent Claim
31 words
The method of claim 20, wherein said aqueous solution is about 0.0005 molar in sulfuric acid and said oxidation agent is hydroen peroxide present in an amount of about 0.004 molar.
Claim 27
Dependent Claim
22 words
The method of claim 20, wherein said exposing step (a) is performed at a temperature of from about 15° to 50° C.
Claim 28
Dependent Claim
43 words
The method of claim 20, wherein the concentration of NO 2 gas in said atmosphere is from about 1.2 to 10 parts per million and the concentration of said NO gas in said atmosphere is from about 2 to 25 parts per million.
Claim 29
Dependent Claim
21 words
The method of claim 20, wherein chloride ion is removed from said aqueous solution after step (a) and before step (b).
Claim 30
Dependent Claim
19 words
The method of claim 26, wherein said chloride ion is removed by the precipitation of an insoluble chlorine compound.
Claim 31
Dependent Claim
13 words
The method of claim 27, wherein said insoluble chlorine compound is silver chloride.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-16 | 1980-05-17 | 1980-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-16 | 1984-05-17 | 1984-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-16 | 1988-05-17 | 1988-11-16 | $7700.00 | Window Closed / Lapsed |