US3897684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent magnet type e.m. current meters
Assignee: United States Department of the Navy
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Filing: 1974-03-25
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Granted: 1975-08-05
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Expires: 1994-03-25
Abstract
Abstract This disclosure makes use of a permanent magnet probe to measure fluid flow and provides means for depolarizing the electrodes used therewith.
Inventors
- 👤 Rajinder N Dewan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:04
CPC Classifications
G; G01; G01P; G01P5/00; G01P5/08; G01C; G01C13/00; G01C13/002; G01C13/006; G01F; G01F1/00; G01F1/56; G01F1/58
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
136 words
A permanent magnetic fluid stream flow meter which comprises: an elongated housing made of nonferromagnetic material; a permanent bar magnet secured within said housing with its long axis coaxial with said housing such that its magnetic lines of flux are perpendicular to the direction of fluid flow to be measured; at least one pair of oppositely disposed electrodes symmetrically positioned about said permanent magnet and so positioned to be in electrical contact with the fluid to be measured; a square wave generator means for periodically applying a square wave current to said electrodes with periods of zero bias on said electrodes; and electrical potential detector means for measuring a potential between said electrodes produced by fluid flow across said magnetic lines of flux during zero bias on said electrodes which is representative of the fluid flow.
Claim 2
Dependent Claim
136 words
A permanent magnetic fluid stream flow meter which comprises: an elongated housing made of nonferromagnetic material; a permanent bar magnet secured within said housing with its long axis coaxial with said housing such that its magnetic lines of flux are perpendicular to the direction of fluid flow to be measured; at least one pair of oppositely disposed electrodes symmetrically positioned about said permanent magnet and so positioned to be in electrical contact with the fluid to be measured; a square wave generator means for periodically applying a square wave current to said electrodes with periods of zero bias on said electrodes; and electrical potential detector means for measuring a potential between said electrodes produced by fluid flow across said magnetic lines of flux during zero bias on said electrodes which is representative of the fluid flow.
Claim 3
Dependent Claim
23 words
A permanent magnetic fluid stream flow meter as claimed in claim 1, wherein; said flow meter includes two pair of orthogonally disposed electrodes.
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) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |