US5541733A
Expired / Lapsed
US
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Method and apparatus for remote detection and thickness measurement of solid or liquid layer
Assignee: National Research Council Canada
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Filing: 1995-01-17
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Granted: 1996-07-30
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Expires: 2015-01-17
Abstract
Abstract There is described a method and apparatus for detection and thickness evaluation of a buildup of a solid, e.g. ice, or liquid on a solid surface, such as ice on a body of an aircraft. The apparatus comprises a source of a narrow beam of radiation and a means for remote evaluation of the size of a luminous area created on the solid surface by the beam. The method of the invention involves measuring the size of the luminous area and determining the thickness of any built-up layer, if sufficiently transparent, using a formula which uses the dependency of the size of the luminous are on the thickness of the layer and the refraction index of the medium. Differentiation between ice and a liquid is possible by evaluating regularity of illumination of the luminous area.
Inventors
- 👤 Robert E. Gagnon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:10
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/06; B; B64; B64F; B64F5/00; B64F5/20
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
96 words
An apparatus for remote thickness evaluation of a substantially transparent layer of solid or a liquid on a substantially smooth surface, the apparatus comprising: a source of electromagnetic radiation for emitting a narrow beam of radiation towards the surface to be examined in a manner to create, in the presence of a substantially transparent solid layer or a liquid layer on the surface, a luminous multi-zone area on the surface, and a remote detecting means for determining the size of the luminous multi-zone area as a function of the thickness of the solid or liquid layer.
Claim 2
Independent Claim
96 words
An apparatus for remote thickness evaluation of a substantially transparent layer of solid or a liquid on a substantially smooth surface, the apparatus comprising: a source of electromagnetic radiation for emitting a narrow beam of radiation towards the surface to be examined in a manner to create, in the presence of a substantially transparent solid layer or a liquid layer on the surface, a luminous multi-zone area on the surface, and a remote detecting means for determining the size of the luminous multi-zone area as a function of the thickness of the solid or liquid layer.
Claim 3
Dependent Claim
14 words
The apparatus of claim 1 wherein the source of electromagnetic radiation is a laser.
Claim 4
Dependent Claim
16 words
The apparatus according to claim 1 where the wavelength of the radiation is below 1 micron.
Claim 5
Dependent Claim
18 words
The apparatus according to claim 1 wherein the detecting means are a video camera with a telephoto lens.
Claim 6
Dependent Claim
17 words
The apparatus according to claim 1 further comprising means for varying the direction of the radiation beam.
Claim 7
Independent Claim
109 words
A method of remote non-contact thickness evaluation of a substantially transparent layer of a solid or a liquid on a substantially smooth surface, comprising the steps of: directing a narrow beam of electromagnetic radiation onto the layer of solid or liquid in a manner to create on the surface a luminous multi-zone area, measuring the size or diameter D of the luminous area, and determining the thickness H of the layer of the solid or liquid from the size or diameter D of the luminous area by way of the formula H=D/4 tan α where α=sin.sup.-1 (1/n) n being the refractive index of the solid or of the liquid.
Claim 8
Independent Claim
109 words
A method of remote non-contact thickness evaluation of a substantially transparent layer of a solid or a liquid on a substantially smooth surface, comprising the steps of: directing a narrow beam of electromagnetic radiation onto the layer of solid or liquid in a manner to create on the surface a luminous multi-zone area, measuring the size or diameter D of the luminous area, and determining the thickness H of the layer of the solid or liquid from the size or diameter D of the luminous area by way of the formula H=D/4 tan α where α=sin.sup.-1 (1/n) n being the refractive index of the solid or of the liquid.
Claim 9
Dependent Claim
54 words
The method according to claim 6 wherein the beam of radiation is directed onto the layer in a manner to create on the surface a luminous multi-zone area having at least two zones, a bright centre zone and a darker second zone, wherein D is the size or diameter of the darker second zone.
Claim 10
Independent Claim
100 words
A method of remote non-contact detection and optional thickness evaluation of a substantially transparent layer of a solid or liquid on a substantially smooth solid surface, comprising the steps of: directing a narrow beam of electromagnetic radiation onto the layer of solid or liquid in a manner to create on the surface, in the presence of such layer, a luminous area having at least two zones, including a bright centre zone and a darker second zone, and determining whether the layer is a liquid or a solid by evaluating the regularity of illumination of at least one of said zones.
Claim 11
Independent Claim
100 words
A method of remote non-contact detection and optional thickness evaluation of a substantially transparent layer of a solid or liquid on a substantially smooth solid surface, comprising the steps of: directing a narrow beam of electromagnetic radiation onto the layer of solid or liquid in a manner to create on the surface, in the presence of such layer, a luminous area having at least two zones, including a bright centre zone and a darker second zone, and determining whether the layer is a liquid or a solid by evaluating the regularity of illumination of at least one of said zones.
Claim 12
Dependent Claim
66 words
The method according to claim 8, further comprising the steps of measuring the size or diameter D of the luminous area, and determining the thickness H of the layer of solid or liquid from the size or diameter D of the luminous area by way of the formula H=D/4 tan α where α=sin.sup.-1 (1/n) n being the refractive index of the solid or of the liquid.
Claim 13
Dependent Claim
18 words
The method according to claim 8, wherein D is the size or diameter of the darker second zone.
References Cited (Backward Citations)
US5400144A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-07-30 | 2000-01-29 | 2000-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-30 | 2004-01-29 | 2004-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-30 | 2008-01-29 | 2008-07-30 | $7700.00 | Window Closed / Lapsed |