US4885529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Identification of fluids and an interface between fluids by measuring complex impedance
Assignee: National Technology and Engineering Solutions of Sandia LLC
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Filing: 1988-03-10
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Granted: 1989-12-05
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Expires: 2008-03-10
Abstract
Abstract Complex impedance measured over a predefined frequency range is used to determine the identity of different oils in a column. The location of an interface between the oils is determined from the percent frequency effects of the complex impedance measured across the interface.
Inventors
- 👤 David O. Lee
- 👤 James R. Wayland, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:06
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
84 words
A method for identifying an interface between two different fluids comprising: measuring, at a plurality of different frequencies over a predetermined frequency range, the complex impedance between spaced electrodes immersed in a fluid; calculating a function of the difference between the maximum complex impedance and the minimum complex impedance measured over said frequency range for a plurality of different fluid levels; and using the fluid level of a discontinuity in said function as an indication of the location of an interface between different fluids.
Claim 2
Independent Claim
84 words
A method for identifying an interface between two different fluids comprising: measuring, at a plurality of different frequencies over a predetermined frequency range, the complex impedance between spaced electrodes immersed in a fluid; calculating a function of the difference between the maximum complex impedance and the minimum complex impedance measured over said frequency range for a plurality of different fluid levels; and using the fluid level of a discontinuity in said function as an indication of the location of an interface between different fluids.
Claim 3
Dependent Claim
83 words
Apparatus for identifying an interface between two different fluids comprising: means for measuring, at a plurality of different frequencies over a predetermined frequency range, the complex impedance between spaced electrodes immersed in the fluids; and means for calculating a function of the difference between the maximum complex impedance and the minimum complex impedance measured over said frequency range for a plurality of different fluid levels; wherein a discontinuity in said function is an indication of the location of an interface between different fluids.
Claim 4
Dependent Claim
83 words
Apparatus for identifying an interface between two different fluids comprising: means for measuring, at a plurality of different frequencies over a predetermined frequency range, the complex impedance between spaced electrodes immersed in the fluids; and means for calculating a function of the difference between the maximum complex impedance and the minimum complex impedance measured over said frequency range for a plurality of different fluid levels; wherein a discontinuity in said function is an indication of the location of an interface between different fluids.
Claim 5
Dependent Claim
13 words
The apparatus of claim 2 wherein said fluids are contained within a column.
Claim 6
Dependent Claim
14 words
The apparatus of claim 2 wherein said calculated function is the percent frequency effects.
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) | 1992-12-04 | 1993-06-05 | 1993-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-04 | 1997-06-05 | 1997-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-04 | 2001-06-05 | 2001-12-05 | $7700.00 | Window Closed / Lapsed |