US3649505A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ammonia sensor
Assignee: Beckman Coulter Inc
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Filing: 1969-03-03
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Granted: 1972-03-14
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Expires: 1989-03-03
Abstract
Abstract AN ELECTROCHEMCIAL CELL FOR MEASURING THE AMMONIA CONTENT OF A SAMPLE. THE CELL COMPRISES A HYDROGEN ION SENSITIVE ELECTRODE, SUCH AS A GLASS ELECTRODE, AND A REFERENCE ELECTRODE JOINED BY AN AMMONIUM ION CONTAINING ELECTROLYTE. THE ELECTRODES AND ELECTRLYTE ARE SEPARATED FROM THE SAMPLE MEDIUM BEING ANALYZED BY MEANS OF A MICROPOROUS HYDROPHOBIC MEMBRANE WHICH IS HIGHLY PERMEABLE TO AMMONIA AND SUBSTANTIALLY IMPERMEABLE TO LIQUID AND IONS. A PREFERRED MEMBRANCE OF THIS CHARACTER IS A MICROPOROUS POLYVINYLIDENE FLUORIDE FILTER MATERIAL.
Inventors
- 👤 Allen Strickler
- 👤 Cedric H Beebe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:52
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/4162
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |