US3721897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wall thickness and temperature monitoring apparatus for boiler tubes
Assignee: AKA APPARATKEMISKA AB
•
Filing: 1971-05-07
•
Granted: 1973-03-20
•
Expires: 1991-05-07
Abstract
Abstract CONTINUOUS OR INTERMITTENT EXAMINATION OF OPERATING CONDITIONS AND OPERATIONAL SAFETY OF THE BOILER TUBES OF A BOILER, DURING OPERATION OF THE BOILER, IS EFFECTED BY PROVIDING AN ELECTRIC CURRENT THROUGH THE WALL MATERIAL OF A BOILER TUBE AND MEASURING THE VOLTAGE DROP BETWEEN POINTS ON THE BOILER TUBE. D R A W I N G
Inventors
- 👤 G Edling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:39
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01B7/06
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |