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Patent US4271125A successfully refreshed from Google Patents.
US4271125A
Expired / Lapsed
US
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Indicator device for the quantitative determination of metal cyanides in aerosol form
Assignee: Draegerwerk AG and Co KGaA
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Filing: 1979-11-13
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Granted: 1981-06-02
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Expires: 1999-11-13
Abstract
Abstract An indicator device for the quantitative determination of aerosol-type metal cyanides, including a tube provided with a bore extending therethrough, a front layer of a substrate material impregnated with sulfuric acid or phosphoric acid and a following indicating layer of a substrate impregnated with mercuric chloride and methyl red.
Inventors
- 👤 Kurt Leichnitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:21
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/223; G01N31/224; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/172307
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
86 words
An indicator device for the quantitative determination of metal cyanides in aerosol form, comprising, a tube having a bore extending therethrough from an entrance end for receiving the metal cyanides to an exit end, gas-permeable means within said bore adjacent said entrance end, said gas-permeable means including a carrier member and an acid impregnated in said carrier member, and indicating means within said bore intermediate said gas-permeable means and said exit end, said indicator means having a carrier member impregnated with mercuric chloride and methyl red.
Claim 2
Dependent Claim
86 words
An indicator device for the quantitative determination of metal cyanides in aerosol form, comprising, a tube having a bore extending therethrough from an entrance end for receiving the metal cyanides to an exit end, gas-permeable means within said bore adjacent said entrance end, said gas-permeable means including a carrier member and an acid impregnated in said carrier member, and indicating means within said bore intermediate said gas-permeable means and said exit end, said indicator means having a carrier member impregnated with mercuric chloride and methyl red.
Claim 3
Dependent Claim
12 words
The device according to claim 1, wherein said acid is sulfuric acid.
Claim 4
Dependent Claim
12 words
The device according to claim 1, wherein said acid is phosphoric acid.
Claim 5
Dependent Claim
23 words
The device according to claim 1, further comprising, pump means connected to said exit end for drawing the metal cyanides through said bore.
Claim 6
Dependent Claim
22 words
The device according to claim 1, wherein the quantity of acid exceeds the relative amount of metal cyanides on a stoichiometric basis.
Claim 7
Dependent Claim
43 words
The device according to claim 1, wherein said gas-permeable means comprises a first layer in said bore and said indicating means comprises a second layer in said bore, and said tube includes only said first layer and said second layer in said base.
Claim 8
Dependent Claim
27 words
The device according to claim 1, wherein said bore of said tube is closed at said entrance end and further comprising means for opening said entrance end.
Claim 9
Dependent Claim
24 words
The device according to claim 7, wherein said tube is glass and said opening means includes a tip which may be readily broken away.
References Cited (Backward Citations)
GB1143818A
Cited
US3223487A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-01 | 1984-12-01 | 1985-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-01 | 1988-12-01 | 1989-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-01 | 1992-12-01 | 1993-06-02 | $7700.00 | Window Closed / Lapsed |