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(12) Patent: | (11) CA 2072522 |
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(54) English Title: | COLORIMETRIC TESTING AND MEASURING DEVICE FOR GASES |
(54) French Title: | DISPOSITIF D'ESSAI ET DE MESURE COLORIMETRIQUE POUR L'ANALYSE DE GAZ |
Status: | Expired and beyond the Period of Reversal |
(51) International Patent Classification (IPC): |
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(72) Inventors : |
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(73) Owners : |
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(71) Applicants : |
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(74) Agent: | SMART & BIGGAR LP |
(74) Associate agent: | |
(45) Issued: | 1995-08-01 |
(22) Filed Date: | 1992-06-26 |
(41) Open to Public Inspection: | 1992-12-30 |
Examination requested: | 1992-06-26 |
Availability of licence: | N/A |
Dedicated to the Public: | N/A |
(25) Language of filing: | English |
Patent Cooperation Treaty (PCT): | No |
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(30) Application Priority Data: | ||||||
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An improved measuring apparatus for the colorimetric
indication of gases is disclosed. The apparatus comprises a
carrier that is impregnated with a solution of a moisture
retainer and a detection indicator. A mixture of sulfolane and
diethylphthalate is used as the moisture retainer. To measure
hydride gases, such as arsine or phosphine, the indicator con-
sists of palladium tetramine chloride. The impregnating solution
may be applied to a paper carrier or to a granular silica gel
carrier. Due to the presence of the moisture retainer, the
moisture required for the indicating reaction remains on the
indicator carrier for a longer period of time, both during stor-
age of the device and during measurements, when the carrier is
exposed to the gaseous substance that is to be indicated.
Note: Claims are shown in the official language in which they were submitted.
Note: Descriptions are shown in the official language in which they were submitted.
Sorry, the representative drawing for patent document number 2072522 was not found.
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Description | Date |
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Inactive: IPC from MCD | 2006-03-11 |
Time Limit for Reversal Expired | 2004-06-28 |
Letter Sent | 2003-06-26 |
Grant by Issuance | 1995-08-01 |
Application Published (Open to Public Inspection) | 1992-12-30 |
All Requirements for Examination Determined Compliant | 1992-06-26 |
Request for Examination Requirements Determined Compliant | 1992-06-26 |
There is no abandonment history.
Fee Type | Anniversary Year | Due Date | Paid Date |
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MF (patent, 6th anniv.) - standard | 1998-06-26 | 1998-05-21 | |
MF (patent, 7th anniv.) - standard | 1999-06-28 | 1999-05-20 | |
MF (patent, 8th anniv.) - standard | 2000-06-26 | 2000-05-26 | |
MF (patent, 9th anniv.) - standard | 2001-06-26 | 2001-05-28 | |
MF (patent, 10th anniv.) - standard | 2002-06-26 | 2002-05-29 |
Note: Records showing the ownership history in alphabetical order.
Current Owners on Record |
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DRAGERWERK AKTIENGESELLSCHAFT |
Past Owners on Record |
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WOLFGANG EVERS |