US3809537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Test for lead
Assignee: Individual
•
Filing: 1972-05-02
•
Granted: 1974-05-07
•
Expires: 1992-05-02
Abstract
Abstract LEAD IN CONCENTRATIONS IN THE RANGE 4-40 P.P.M. IN AQUEOUOUS SOLUTION OF PH 1-5 IS VISUALLY DETECTED BY ADDING A SOLUTION OF A SOLUBLE SULFIDE.
Inventors
- 👤 A Horine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:46
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/02; G01N31/22
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) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |