US2823984A
Expired / Lapsed
US
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Fluoride ion indicator and process of development
Assignee: Boyce Thompson Institute
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Filing: 1955-01-18
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Granted: 1958-02-18
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Expires: 1975-01-18
Abstract
No abstract record available.
Inventors
- 👤 Radu A W Mavrodineanu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:00
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N33/00; G01N33/18; Y; Y10; Y10T; Y10T436/00; Y10T436/19
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
THE PROCESS OF DETERMINING THE PRESENCE OF FLUORIDE IONS IN A GAS WHICH COMPRISES SUSPENDING IN THE GAS AN INDICATOR HAVING AN ABSORBING SURFACE INITIALLY IMPREGNATED WITH A NITRATE OF THE GROUP CONSISTING OF ZIRCONIUM NITRATE AND THORIUM NITRATE AND THENCE IMPREGNATED WITH A DYE THAT FORMS A LAKE WITH THE NITRATE, WHEREBY SAID LAKE IS CONCENTRATED PRIMARILY AT THE ABSORBING SURFACE, A PORTION OF SAID INDICATOR BEING COVERED WITH A REMOVABLE MATERIAL WHICH IS IMPERVIOUS TO THE FLUORIDE IONS, REMOVING THE COVER, AND IMMERSING THE INDICATOR IN AN ACID SOLUTION TO DEVELOP THE COLOR CHANGE RESULTING FROM THE CONTACT OF FLUORIDE IONS WITH THE EXPOSED PART OF THE INDICATOR.
Claim 2
Dependent Claim
110 words
THE PROCESS OF DETERMINING THE PRESENCE OF FLUORIDE IONS IN A GAS WHICH COMPRISES SUSPENDING IN THE GAS AN INDICATOR HAVING AN ABSORBING SURFACE INITIALLY IMPREGNATED WITH A NITRATE OF THE GROUP CONSISTING OF ZIRCONIUM NITRATE AND THORIUM NITRATE AND THENCE IMPREGNATED WITH A DYE THAT FORMS A LAKE WITH THE NITRATE, WHEREBY SAID LAKE IS CONCENTRATED PRIMARILY AT THE ABSORBING SURFACE, A PORTION OF SAID INDICATOR BEING COVERED WITH A REMOVABLE MATERIAL WHICH IS IMPERVIOUS TO THE FLUORIDE IONS, REMOVING THE COVER, AND IMMERSING THE INDICATOR IN AN ACID SOLUTION TO DEVELOP THE COLOR CHANGE RESULTING FROM THE CONTACT OF FLUORIDE IONS WITH THE EXPOSED PART OF THE INDICATOR.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-02-17 | 1961-08-19 | 1962-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-17 | 1965-08-19 | 1966-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-17 | 1969-08-19 | 1970-02-18 | $7700.00 | Window Closed / Lapsed |