Patent US5070730A successfully refreshed from Google Patents.
US5070730A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for level gauging with microwaves
Assignee: Rosemount Tank Radar AB
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Filing: 1990-03-27
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Granted: 1991-12-10
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Expires: 2010-03-27
Abstract
Abstract A device for gauging the level of a fluid in a container having a gas above the surface of the fluid. The device comprises a microwave transmitter transmitting a microwave radio signal through the gas to the surface and a receiver for receiving the microwave signal reflected by the surface. An electronic unit is arranged to calculate from the propagation time of the microwave signal a first distance from the transmitter to the surface of the fluid and thereby the level in the container. The microwave signal is preferably within the radar frequency range. A sound transmitter is also provided for transmitting a sound signal through the gas to the surface of the fluid and is capable of receiving a sound signal reflected from the surface of the fluid. A means is provided for correcting the first distance to a second corrected distance as a function of the microwave velocity and the known relation between the sound velocity and the microwave velocity.
Inventors
- 👤 Kurt O. Edvardsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:22
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01S; G01S7/00; G01S7/02; G01S7/40; G01S7/4004; G01F23/284; G01F23/296; G01F23/2962; G01S13/00; G01S13/86; G01S13/862; G01S13/88; Y; Y10; Y10S; Y10S367/00; Y10S367/908
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
136 words
A device for gauging the level of a fluid in a container, above the surface of the fluid there being a gas, the device comprising a first transmitter for transmitting a microwave signal through said gas towards the surface of the fluid, a first receiver for receiving the microwave signal reflected against said surface, an electronic unit arranged to calculate from the propagation time of the emitted and reflected microwave signal a first distance from the first transmitter to the surface of the fluid and thereby its level in the container, characterized by a first means for gauging the sound velocity in said gas and a second means for correcting said first distance to a second distance as a function of the microwave velocity and a known relation between the sound velocity and the microwave velocity.
Claim 2
Independent Claim
136 words
A device for gauging the level of a fluid in a container, above the surface of the fluid there being a gas, the device comprising a first transmitter for transmitting a microwave signal through said gas towards the surface of the fluid, a first receiver for receiving the microwave signal reflected against said surface, an electronic unit arranged to calculate from the propagation time of the emitted and reflected microwave signal a first distance from the first transmitter to the surface of the fluid and thereby its level in the container, characterized by a first means for gauging the sound velocity in said gas and a second means for correcting said first distance to a second distance as a function of the microwave velocity and a known relation between the sound velocity and the microwave velocity.
Claim 3
Dependent Claim
42 words
A device according to claim 1, characterized in that said first means is arranged to emit a sound signal parallel to said microwave signal towards the surface of the fluid, and is arranged to receive the sound signal reflected against said surface.
Claim 4
Dependent Claim
39 words
A device according to claim 1, characterized in that the first means and the transmitter of a microwave signal are combined to a unit, preferably arranged to transmit the sound signal and the microwave signal essentially the same way.
Claim 5
Dependent Claim
27 words
A device according to claim 3, characterized in that said unit comprises a horn arranged to give directivity to both the sound signal and the microwave signal.
Claim 6
Dependent Claim
35 words
A device according to claim 1, characterized in that the first means for gauging the sound velocity comprises a second transmitter and a second receiver, both preferably located in the upper portion of the container.
Claim 7
Dependent Claim
105 words
A device according to claim 5, characterized in that a third means, constituting a computer that comprises a memory unit for storing a first gauge value of the sound velocity for a relatively high level of the fluid in the container, further comprising a calculating unit for calculating the sound velocity in a gas showing a density gradient, starting out from the first stored gauge value and a recently gauged second gauge value for the sound velocity corresponding to a relatively lower level of the fluid in the container, and from an algorithm stored in the computer describing a probable density gradient in the gas.
References Cited (Backward Citations)
US2960078A
Cited
US3286098A
Cited
US3184969A
Cited
US4101865A
Cited
SU631786A1
Cited
US4221004A
Cited
US4578997A
Cited
US4661817A
Cited
US4675854A
Cited
US4641139A
Cited
US4641139B1
Cited
US4566321A
Cited
US4700567A
Cited
US4670754A
Cited
US4785664A
Cited
JPS6465420A
Cited
US4821569A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-09 | 1995-06-10 | 1995-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-09 | 1999-06-10 | 1999-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-09 | 2003-06-10 | 2003-12-10 | $7700.00 | Window Closed / Lapsed |