Oil Thickness Measurement Using Laser Refraction

<p>Abstract: The thickness of oil spills on the sea is an important but poorly studied topic. Means to measure slick thickness are reviewed. More than 30 concepts are summarized. Many of these are judged not to be viable for a variety of scientific reasons. Two means are currently available to remotely measure oil thickness, namely, passive microwave radiometry and time of acoustic travel. Microwave radiometry is commercially developed at this time. Visual means to ascertain oil thickness are restricted by physics to thicknesses smaller than those of rainbow sheens (~3 &#181;m), which rarely occur on large spills, and thin sheen. One can observe that some slicks are not sheen and are probably thicker. These three thickness regimes are not useful to oil spill countermeasures, as most of the oil is contained in the thick portion of a slick, the thickness of which is unknown and ranges over several orders of magnitude. There is a continuing need to measure the thickness of oil spills. This need continues to increase with time, and further research effort is needed. Several viable concepts have been developed but require further work and verification. One of the difficulties is that ground truthing and verification methods are generally not available for most thickness measurement methods.</p>

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Real-Time Thickness Measurement of Marine Oil Spill by Fiber-Optic Surface Plasmon Resonance Sensors

Frontiers in Marine Science ◽

10.3389/fmars.2021.764970 ◽

2022 ◽

Vol 8 ◽

Author(s):

Huiting Yin ◽

Shaohuang Chen ◽

Renliang Huang ◽

Heng Chang ◽

Jiayue Liu ◽

...

Keyword(s):

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Oil Spills ◽

Thickness Measurement ◽

Detection Sensitivity ◽

Marine Oil ◽

Oil Slick ◽

Marine Oil Spills ◽

Oil Thickness

Rapid detection of marine oil spills is becoming increasingly critical in the face of frequent marine oil spills. Oil slick thickness measurement is critical in the hazard assessment of such oil leaks. As surface plasmon resonance (SPR) sensors are sensitive to slight changes in refractive index, they can monitor offshore oil spills arising from significant differences in the refractive index between oil and water. This study presents a gold-film fiber-optic surface plasmon resonance (FOSPR) sensor prepared by polydopamine accelerated wet chemical plating for rapid and real-time measurement of oil slick thickness. We examined oil thickness detection at two interfaces, namely, water-oil and air-oil. Detection sensitivity of −1.373%/mm is obtained at the water-oil interface in the thickness range of 0–5 mm; detection sensitivity of −2.742%/mm is obtained at the air-oil interface in the thickness range of 0–10 mm. Temperature and salinity present negligible effects on the oil slick thickness measurement. The fabricated FOSPR sensor has the ability to detect the presence of oil as well as quantify the oil thickness. It has favorable repeatability and reusability, demonstrating the significant potential for use in the estimation of marine oil slick thickness.

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Oil Thickness Measurement by Light Absorption Analysis

Journal of the Korean Society for Marine Environment & Energy ◽

10.7846/jkosmee.2013.16.4.263 ◽

2013 ◽

Vol 16 (4) ◽

pp. 263-267 ◽

Cited By ~ 3

Author(s):

Sangwoo Oh ◽

Moonjin Lee

Keyword(s):

Light Absorption ◽

Thickness Measurement ◽

Absorption Analysis ◽

Oil Thickness

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MAPPING OIL SPILL THICKNESS WITH A PORTABLE MULTISPECTRAL AERIAL IMAGER

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-2008-1-131 ◽

2008 ◽

Vol 2008 (1) ◽

pp. 131-136 ◽

Cited By ~ 7

Author(s):

Jan Svejkovsky ◽

Judd Muskat ◽

Joseph Mullin

Keyword(s):

Imaging System ◽

Rapid Determination ◽

Free Water ◽

Image Data ◽

Visual Assessment ◽

Thickness Measurement ◽

Measurement Range ◽

Additional Information ◽

Natural Oil ◽

Oil Thickness

ABSTRACT Rapid determination of oil thickness patterns within a spill at sea is vital for efficient planning and management of spill response activities. Presently such determinations are made almost solely by airborne visual surveys which require specially trained observers and are prone to errors due to variations in illumination, water color, and other environmental conditions. Our goal is to eliminate the subjectivity of visual assessment techniques by developing a computerized portable imaging system that could provide detailed maps of oil-on-water thickness distributions in near-realtime. We have developed oil thickness determination algorithms that utilize multispectral images from a 4-channel sensor providing oil reflectance data in the UV and three channels between 500 and 700nm. A neural network-based algorithm first isolates all oil-on-water areas from oil-free water, sunglint and other potential artifacts. A fuzzy ratio classification algorithm then maps the oil-contaminated areas for thickness classes. The reflectance ratio-based algorithms were tested with several types of crude and fuel oils at MMS’ Ohmsett facility as well as over natural oil seepage areas in the Santa Barbara Channel, California. The methodology yielded accurate thickness estimates over oil films ranging from sheens to 0.2–0.3mm thick. Although the location of thicker films can be accurately mapped, their absolute thickness cannot be established using the UV-visible wavelength range. The addition of an infrared channel may expand the system'S thickness measurement range and is presently being investigated. The imager also allows the identification of emulsified vs. unemulsified oil, thus providing additional information to help guide efficient spill response. Real-time image processing capabilities are presently being developed to allow the system to disseminate a GIS-compatible map immediately after image data acquisition.

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Experimental determination of the system parameter of oil thickness measurement

10.1117/12.870208 ◽

2010 ◽

Author(s):

Qieni Lu ◽

Hao Wu ◽

Di Wu

Keyword(s):

Experimental Determination ◽

System Parameter ◽

Thickness Measurement ◽

Oil Thickness

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Thickness Measurement in the AEM by Macintosh-Based Analysis of Two-Beam Convergent Beam Patterns

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010013612x ◽

1990 ◽

Vol 48 (2) ◽

pp. 504-505

Author(s):

John F. Mansfield ◽

Douglas C. Crawford

Keyword(s):

Electron Microscope ◽

Video Camera ◽

Thickness Measurement ◽

Specimen Thickness ◽

Crystalline Materials ◽

Beam Dynamic ◽

Line Measurement ◽

On Line ◽

Image Position ◽

Convergent Beam

A method has been developed that allows on-line measurement of the thickness of crystalline materials in the analytical electron microscope. Two-beam convergent beam electron diffraction (CBED) patterns are digitized from a JEOL 2000FX electron microscope into an Apple Macintosh II microcomputer via a Gatan #673 CCD Video Camera and an Imaging Systems Technology Video 1000 frame-capture board. It is necessary to know the lattice parameters of the sample since measurements are made of the spacing of the diffraction discs in order to calibrate the pattern. The sample thickness is calculated from measurements of the spacings of the fringes that are seen in the diffraction discs. This technique was pioneered by Kelly et al, who used the two-beam dynamic theory of MacGillavry relate the deviation parameter (Si) of the ith fringe from the exact Bragg condition to the specimen thickness (t) with the equation:Where ξg, is the extinction distance for that reflection and ni is an integer.

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