Browsing by Subject "optical tomography"

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Access status: Open Access ,
A dual modality reconstruction algorithm for optical and electrical capacitance tomography
(Wydawnictwa AGH, 2006) Mosorov, Volodymyr; Sankowski, Dominik; Zain, Rasif Mohd
The paper presents a novel concept combining electrical capacitance and optical tomography for monitoring and investigating of solid/gas flows. The main idea is to gain a high quality image in full-scale concentration distribution of solid/gas flow. The new image reconstruction algorithm is developed.
Access status: Open Access ,
Metody wyznaczania map czułości dla systemu tomografii optycznej
(Wydawnictwa AGH, 2007) Przywarski, Rafał; Grudzień, Krzysztof; Romanowski, Andrzej; Rząsa, Mariusz R.; Wajman, Radosław
Image reconstruction is a first stage of deriving information about the industrial process state for majority of process tomography applications. Therefore, image preparation on the base of tomography modality-specific properties, is the most important step in phenomena investigation with use of tomography. For optical modality, visual properties of the medium present in an explored space is deployed. Measurement space are illuminated with a few beams of visible light rays, and after traveling through the examined region, the incident light is sensed with detectors. Based on differences in medium transparency level and some other phenomena like reflection, refraction, etc., the image corresponding to a given space. The process of image reconstruction utilizes the sensitivity matrix. The paper presents two methods of sensitivity matrix determination. The first one assumes the light rays to be segments. The other one makes an assumption of the fixed width of light beams. Both methods are using the concept of light tracking from source to detector. The comparison of both methods identifies advantages and disadvantages of the two solutions. The study was conducted with use of numerical simulation and multiphase (gas/liquid) flow experiments in vertical column.
Access status: Open Access ,
Optyczny tomograf procesowy składający się z pięciu projekcji
(Wydawnictwa AGH, 2007) Rząsa, Mariusz R.; Grudzień, Krzysztof; Romanowski, Andrzej; Wajman, Radosław
The paper presents the optical tomograph in which a tested object is illuminated from five locations. Measurement of luminous intensity is changed into a discrete signal (0 or 1) in the detectors including 64 optical sensors. Next, the measuring results are subjected to reconstruction according to a matrix algorithm of reconstruction. A detailed description of the measurement sensor is presented in the paper. The paper covers a discussion on the principle of operation of the electronic system for changing a light signal received by the detector into a discrete electronic signal. The authors describe a path of the light beam, taking into account optical phenomena occurring at the phase boundary white light is passing through the sensor wall and phenomena inside the measurement space. A method of the sensor calibration is analyzed and a way of technical realization of the presented problem is discussed, as well. The presented idea was elaborated in order to test two-phase, gas-liquid flows however, it can be also applied in tests of other objects with a distinct phase boundary.