US5290704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of detecting organic solvent vapors
Assignee: Valence Technology Inc
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Filing: 1993-03-19
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Granted: 1994-03-01
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Expires: 2013-03-19
Abstract
Abstract A photometric detector is used to detect the presence of organic solvent vapors in the air. The detector need only be exposed to the air in the area to be tested. The optical density, i.e. darkness of the color of the detector determines the cumulative amount of solvent vapor exposure and the rate at which the dark color develops determines the concentration of solvent vapors in the air. This method can be used to quickly and easily test for harmful levels of toxic organic solvent vapors in the workplace or elsewhere.
Inventors
- 👤 On-Kok Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:12
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0027; G01N33/0036; G01N33/0047; G01N21/00; G01N21/75; G01N21/77; G01N21/78; G01N21/783; G01N31/00; G01N31/22; G01N31/223; G01N31/224; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/200833
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
85 words
A method of detecting organic solvent vapor comprises the steps of: (a) exposing a solvent vapor detector to solvent vapor; and (b) photometrically measuring the optical density of said detector; wherein said detector comprises: a substrate; a binder means which is substantially soluble to said solvent vapor; an electron donating chromogenic composition dispersed on said substrate in connection with said binder means; and an electron accepting composition, which forms a color with said chromogenic composition, dispersed on said substrate in connection with said binder means.
Claim 2
Independent Claim
85 words
A method of detecting organic solvent vapor comprises the steps of: (a) exposing a solvent vapor detector to solvent vapor; and (b) photometrically measuring the optical density of said detector; wherein said detector comprises: a substrate; a binder means which is substantially soluble to said solvent vapor; an electron donating chromogenic composition dispersed on said substrate in connection with said binder means; and an electron accepting composition, which forms a color with said chromogenic composition, dispersed on said substrate in connection with said binder means.
Claim 3
Dependent Claim
23 words
The method of claim 1, wherein said organic solvent comprises at least one polar solvent having a dieletric constant greater than about 8.
Claim 4
Dependent Claim
17 words
The method of claim 2, wherein said polar solvent has a dieletric constant greater than about 12.
Claim 5
Dependent Claim
17 words
The method of claim 3, wherein said polar solvent has a dieletric constant greater than about 16.
Claim 6
Dependent Claim
29 words
The method of claim 2, wherein said polar solvent comprises at least one alcohol, glycol, polyol, aldehyde, carbonate, acetone, ester, ether, ketone, dimethylsulfoxide, glyme, dioxalane, sulfulane, gamma-butyrolactone and tetrahydrofuran.
Claim 7
Dependent Claim
15 words
The method of claim 5, wherein said alcohol contains less than about 8 carbon atoms.
Claim 8
Dependent Claim
15 words
The method of claim 5, wherein said ketone contains less than about 6 carbon atoms.
Claim 9
Dependent Claim
15 words
The method of claim 5, wherein said esters contain less than about 8 carbon atoms.
Claim 10
Dependent Claim
17 words
The method of claim 1, wherein said detector comprises a photometer sensitive to visible or ultraviolet light.
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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) | 1997-02-28 | 1997-08-30 | 1998-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-28 | 2001-08-30 | 2002-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-28 | 2005-08-30 | 2006-03-01 | $7700.00 | Window Closed / Lapsed |