Patent US5000919A successfully refreshed from Google Patents.
US5000919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Testing tube construction for testing gases which are dissolved in liquids and a method of making the same
Assignee: Draegerwerk AG and Co KGaA
•
Filing: 1988-09-28
•
Granted: 1991-03-19
•
Expires: 2008-09-28
Abstract
Abstract A colorimetric test tube having a colorimetric indication which includes a simple detection system for testing gases dissolved in liquids. The test tube has an indicator for the colorimetric indication of gaseous substances to be detected and it has an opening covered against the environment to be tested with a hydrophobic membrane which is permeable to the substances whose presence is to be detected and which can be used for indicating the presence of gases dissolved in liquids. The membrane is advantageously sealed with a covering which dissolves upon immersion of the test tube in a liquid.
Inventors
- 👤 Johannes Heckmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:40
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/223; G01N31/224; Y; Y10; Y10T; Y10T436/00; Y10T436/25; Y10T436/25375; Y10T436/255
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
76 words
A tube for testing substances, comprising a tube body, an indicator for the colorimetric indication of substances to be detected arranged in said tube body, said tube body having an opening in the direction of the environment to be investigated, a hydrophobic polymer membrane permeable to the substance to be detected closing the opening, said tube being useable for indicating gases dissolved in liquids and a coating sealing said membrane which is soluble in a liquid.
Claim 2
Dependent Claim
76 words
A tube for testing substances, comprising a tube body, an indicator for the colorimetric indication of substances to be detected arranged in said tube body, said tube body having an opening in the direction of the environment to be investigated, a hydrophobic polymer membrane permeable to the substance to be detected closing the opening, said tube being useable for indicating gases dissolved in liquids and a coating sealing said membrane which is soluble in a liquid.
Claim 3
Dependent Claim
12 words
A test tube according to claim 1, wherein said membrane is cup-shaped.
Claim 4
Dependent Claim
32 words
A test tube according to claim 1, wherein said membrane comprises a closed tip formation formed at the end of said tube adjacent the opening which is severable to expose the opening.
Claim 5
Dependent Claim
13 words
A tube according to claim 1, wherein said coating comprises a lithium chloride.
Claim 6
Dependent Claim
13 words
A tube according to claim 1, wherein said coating comprises a copper sulfate.
Claim 7
Dependent Claim
23 words
A tube according to claim 1, wherein said tube body is filled at its end opposite to the opening with an air-filled chamber.
Claim 8
Dependent Claim
73 words
A tube for testing substances, comprising a tube body, an indicator for the colorimetric indication of substances to be detected arranged in said tube body, said tube body having an opening in the direction of the environment to be investigated, a hydrophobic membrane permeable to the substance to be detected closing the opening, and a liquid-soluble coating comprising a salt sealing said membrane, said tube being useable for indicating gases dissolved in liquids.
Claim 9
Dependent Claim
73 words
A tube for testing substances, comprising a tube body, an indicator for the colorimetric indication of substances to be detected arranged in said tube body, said tube body having an opening in the direction of the environment to be investigated, a hydrophobic membrane permeable to the substance to be detected closing the opening, and a liquid-soluble coating comprising a salt sealing said membrane, said tube being useable for indicating gases dissolved in liquids.
Claim 10
Independent Claim
62 words
A method for manufacturing a coating which is used to coat a membrane which is placed over a testing tube containing a colorimetric indicating material comprising wetting a membrane in a hot saturated solution of salt and which thereby forms a property for sealing the test tube and having an addition of a wetting agent in excess, and subsequently evaporating the solvent.
Claim 11
Independent Claim
62 words
A method for manufacturing a coating which is used to coat a membrane which is placed over a testing tube containing a colorimetric indicating material comprising wetting a membrane in a hot saturated solution of salt and which thereby forms a property for sealing the test tube and having an addition of a wetting agent in excess, and subsequently evaporating the solvent.
Claim 12
Dependent Claim
21 words
A method according to claim 8, wherein during wetting a low pressure is created on the interior of the test tube.
Claim 13
Dependent Claim
34 words
A method according to claim 8, wherein the coating is manufactured as a closed additional tip for the testing tube which is connected thereto so as to be breakable away from the testing tube.
References Cited (Backward Citations)
US2929687A
Cited
US4071319A
Cited
US4275031A
Cited
US4325890A
Cited
CA1157355A
Cited
US4557902A
Cited
GB2170599A
Cited
US4790857A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-18 | 1994-09-17 | 1995-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-18 | 1998-09-17 | 1999-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-18 | 2002-09-17 | 2003-03-19 | $7700.00 | Window Closed / Lapsed |