Patent US4420567A successfully refreshed from Google Patents.
US4420567A
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Hydride gas detecting tape
Assignee: MDA Scientific Inc
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Filing: 1981-10-22
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Granted: 1983-12-13
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Expires: 2001-10-22
Abstract
Abstract A tape coated with an adsorbent and impregnated with a processing solution which includes silver nitrate, an acid, an alcohol and a glycol is a sensitive detecting means for hydride gases and is stable upon exposure to light.
Inventors
- 👤 Roberta McMahon
- 👤 Franco F. Fiorese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:55
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/8483; G01N1/00; G01N1/28; G01N1/2813; G01N2001/2826; Y; Y10; Y10T; Y10T436/00; Y10T436/16; Y10T436/17; Y10T436/172307
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
71 words
A substrate for detecting hydride gases comprising a solid absorbent material and a detector composition impregnating the absorbent material, said detector composition consisting essentially of silver nitrate, an organic or inorganic acid to stabilize the silver nitrate and a glycol to maintain the substrate in a moist condition whereby the substrate is capable of reaction with a hydride gas for the development of color as a measure of the hydride concentration.
Claim 2
Dependent Claim
71 words
A substrate for detecting hydride gases comprising a solid absorbent material and a detector composition impregnating the absorbent material, said detector composition consisting essentially of silver nitrate, an organic or inorganic acid to stabilize the silver nitrate and a glycol to maintain the substrate in a moist condition whereby the substrate is capable of reaction with a hydride gas for the development of color as a measure of the hydride concentration.
Claim 3
Dependent Claim
26 words
A substrate according to claim 1 wherein said adsorbent material is selected from the group consisting of silicic acid, magnesium silicate, magnesium oxide and aluminum oxide.
Claim 4
Dependent Claim
31 words
A substrate according to claim 1 wherein said absorbent material is impregnated with silver nitrate in an amount within the range of 0.5-2.0% by weight of silver nitrate in the solution.
Claim 5
Dependent Claim
28 words
A substrate according to claim 1 wherein said acid is selected from the group consisting of nitric acid, sulfuric acid, phosphoric acid, glacial acetic acid and trichloroacetic acid.
Claim 6
Dependent Claim
24 words
A substrate according to claim 1 wherein said acid is present in an amount within the range of 0.1-5.0% by volume of the solution.
Claim 7
Dependent Claim
24 words
A substrate according to claim 1 wherein said glycol is selected from the group consisting of ethylene glycol, propylene glycol, trimethylene glycol and glycerol.
Claim 8
Dependent Claim
24 words
A substrate according to claim 1 wherein said glycol is present in an amount within the range of 5-20% by volume of the solution.
Claim 9
Independent Claim
120 words
A method for detecting hydride gases comprising: (a) contacting a hydride-containing gas with a substrate for detecting hydride gases comprising a solid absorbent material impregnated with a detector composition, said detector composition consisting essentially of silver nitrate, an organic or inorganic acid to stabilize the silver nitrate and a glycol to maintain the substrate in a moist condition whereby the substrate is capable of reaction with a hydride-containing gas for the development of color; (b) sampling said hydride-containing gas over a given period of time by allowing diffusion of said gas onto the porous member to produce the detectable color; and (c) determining the intensity of the color as a measure of the concentration of hydride gases in the atmosphere.
Claim 10
Independent Claim
120 words
A method for detecting hydride gases comprising: (a) contacting a hydride-containing gas with a substrate for detecting hydride gases comprising a solid absorbent material impregnated with a detector composition, said detector composition consisting essentially of silver nitrate, an organic or inorganic acid to stabilize the silver nitrate and a glycol to maintain the substrate in a moist condition whereby the substrate is capable of reaction with a hydride-containing gas for the development of color; (b) sampling said hydride-containing gas over a given period of time by allowing diffusion of said gas onto the porous member to produce the detectable color; and (c) determining the intensity of the color as a measure of the concentration of hydride gases in the atmosphere.
Claim 11
Dependent Claim
16 words
A method in accordance with claim 8 wherein the contacting, sampling and measuring is performed continuously.
Claim 12
Dependent Claim
30 words
A method in accordance with claim 8 wherein the intensity of the color is determined electronically to produce a graph of gas concentration versus time over a known time period.
Claim 13
Independent Claim
92 words
A method for detecting and measuring hydride gases comprising the steps of contacting a hydride-containing gas with a solid absorbent material impregnated with a protector composition, said detector composition consisting essentially of silver nitrate, an organic or inorganic acid to stabilize the silver nitrate and a glycol to maintain the substrate in a moist condition or reaction with a hydride gas whereby the substrate develops color in response to a reaction with hydride gas, and determining the intensity of the color developed as a measure of the concentration of the hydride gas.
Claim 14
Independent Claim
92 words
A method for detecting and measuring hydride gases comprising the steps of contacting a hydride-containing gas with a solid absorbent material impregnated with a protector composition, said detector composition consisting essentially of silver nitrate, an organic or inorganic acid to stabilize the silver nitrate and a glycol to maintain the substrate in a moist condition or reaction with a hydride gas whereby the substrate develops color in response to a reaction with hydride gas, and determining the intensity of the color developed as a measure of the concentration of the hydride gas.
References Cited (Backward Citations)
US4211532A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-12 | 1987-06-13 | 1987-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-12 | 1991-06-13 | 1991-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-12 | 1995-06-13 | 1995-12-13 | $7700.00 | Window Closed / Lapsed |