US5073720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level and volume measurement device
Assignee: United States Department of the Navy
•
Filing: 1990-07-30
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Granted: 1991-12-17
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Expires: 2010-07-30
Abstract
Abstract The liquid level measurement device is an electro-optical device which uses light source (typically a light emitting diode (LED) or laser diode) and an optical detector to measure the level of a liquid in a container. The light beam is passed through the liquid and received by the optical detector. The detector output is processed to determine the liquid level or the liquid volume. A special feature is the ability to measure a continuum of fluid levels or volumes.
Inventors
- 👤 Gair D. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 07:52
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284; G01F23/292
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
94 words
A liquid level and volume measuring device for measuring a continuum of liquid levels or volumes of a fluid contained in a transparent or semi-transparent vessel comprising: means for emitting a constant power light beam through the depth of the fluid to be measured, wherein said light beam has a wavelength to match spectral absorptive characteristics of the fluid; means for detecting said light beam exiting the fluid; means for calculating a continuum of fluid levels or volume levels in the fluid under test from the attenuation of said light beam by the fluid.
Claim 2
Dependent Claim
94 words
A liquid level and volume measuring device for measuring a continuum of liquid levels or volumes of a fluid contained in a transparent or semi-transparent vessel comprising: means for emitting a constant power light beam through the depth of the fluid to be measured, wherein said light beam has a wavelength to match spectral absorptive characteristics of the fluid; means for detecting said light beam exiting the fluid; means for calculating a continuum of fluid levels or volume levels in the fluid under test from the attenuation of said light beam by the fluid.
Claim 3
Dependent Claim
141 words
A liquid level and volume measuring device for measuring a continuum of liquid levels or volumes in a transparent or semi-transparent vessel comprising: an optical source for generating light having a wavelength that matches spectral absorptive characteristics of a fluid contained in the vessel; an optical detector to detect light emitted by said optical source; an optical subassembly to direct light from said optical source through the depth of the fluid to be measured onto said optical detector; an optical drive circuit to energize said optical source whereby the average light level emitted by said optical source is substantially constant; and analysis circuitry to analyze the light detected by said optical detector whereby a continuum of levels and volumes of fluid can be accurately determined by calculating the attenuation of the light emitted by said optical source resulting from the fluid.
Claim 4
Dependent Claim
141 words
A liquid level and volume measuring device for measuring a continuum of liquid levels or volumes in a transparent or semi-transparent vessel comprising: an optical source for generating light having a wavelength that matches spectral absorptive characteristics of a fluid contained in the vessel; an optical detector to detect light emitted by said optical source; an optical subassembly to direct light from said optical source through the depth of the fluid to be measured onto said optical detector; an optical drive circuit to energize said optical source whereby the average light level emitted by said optical source is substantially constant; and analysis circuitry to analyze the light detected by said optical detector whereby a continuum of levels and volumes of fluid can be accurately determined by calculating the attenuation of the light emitted by said optical source resulting from the fluid.
Claim 5
Dependent Claim
41 words
A liquid level and volume measurement device of claim 1 wherein said optical subassembly comprises optical fibers from said optical source and said optical detector to a pair of lenses operatively spaced on opposing sides of the fluid to be measured.
Claim 6
Dependent Claim
22 words
A liquid level and volume measurement device according to claim 1 wherein said means for emitting a light beam is a laser.
Claim 7
Dependent Claim
22 words
A liquid level and volume measurement device according to claim 1 wherein said means for emitting a light beam is a LED.
Claim 8
Dependent Claim
18 words
A liquid level and volume measurement device according to claim 2 wherein said optical source is a laser.
Claim 9
Dependent Claim
18 words
A liquid level and volume measurement device according to claim 2 wherein said optical source is a LED.
Claim 10
Dependent Claim
30 words
A liquid level and volume measurement device according to claim 1 wherein said means for emitting is integral with the bottom of the vessel containing the fluid to be measured.
Claim 11
Dependent Claim
32 words
A liquid level and volume measurement device according to claim 1 wherein said means for detecting is an integral part of the bottom of the vessel containing the fluid to be measured.
Claim 12
Independent Claim
83 words
A method of determining the level or volume of a fluid in a transparent or semitransparent vessel comprising the steps of: (a) directing a controlled constant power beam of light through the depth of the fluid to be measured, wherein the controlled beam has a wavelength to match spectral absorptive characteristics of the fluid; (b) detecting the controlled beam exiting the fluid; (c) calculating continuously the level or volume of the fluid by determining the attenuation of the controlled beam exiting the fluid.
Claim 13
Independent Claim
83 words
A method of determining the level or volume of a fluid in a transparent or semitransparent vessel comprising the steps of: (a) directing a controlled constant power beam of light through the depth of the fluid to be measured, wherein the controlled beam has a wavelength to match spectral absorptive characteristics of the fluid; (b) detecting the controlled beam exiting the fluid; (c) calculating continuously the level or volume of the fluid by determining the attenuation of the controlled beam exiting the fluid.
Claim 14
Dependent Claim
28 words
A liquid level and volume measuring device as in claim 1 wherein the fluid is water based and the wavelength of said light beam is approximately 1300 nanometers.
Claim 15
Dependent Claim
28 words
A liquid level and volume measuring device as in claim 2 wherein the fluid is water based and the wavelength of the generated light is approximately 1300 nanometers.
Claim 16
Dependent Claim
32 words
A method of determining the level or volume of a fluid according in claim 10 wherein the fluid is water based and the wavelength of the controlled beam is approximately 1300 nanometers.
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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) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |