US3561254A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring the permeability of porous walls
Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1968-08-05
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Granted: 1971-02-09
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Expires: 1988-08-05
Abstract
Abstract A DEVICE FOR MEASURING THE PERMEABILITY OF POROUS WALLS, ESPECIALLY MICROPOROUS BARRIERS, AND FOR MEASURING THE DISTRIBUTION OF PORE RADII. TWO COMPARTMENTS OF A SEALED ENCLOSURE ARE SEPARATE BY THE POROUS WALL. A SINUSOIDAL PRESSURE VARIATION IS PRODUCED WITHIN ONE OF SAID COMPARTMENTS AND THE PHASE OF THE VARIATION WHICH IS TRANSMITTED INTO THE OTHER COMPARTMENT THROUGH SAID POROUS WALL IS COMPARED WITH THE PHASE OF A SINUSOIDAL CURRENT PRODUCED BY A STRAIGHT FORM POLENTIOMETER WITH A SLIDING CONTACT TO MEASURE THE PHASE SHIFT PRODUCED BY TRANSMISSION THROUGH SAID POROUS WALL AND THEREBY GIVE A INDICATION OF THE PREMEABILITY OF SAID POROUS WALL.
Inventors
- 👤 Henri Argaud
- 👤 Charles Eyraud
- 👤 Daniel Massignon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:27
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |