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We introduce ultra high speed electron beam tomography as a new imaging tool for multiphase flow measurement and small animal imaging. The technique is based on imaging with X-rays produced by a rapidly scanned electron beam instead of a mechanically rotating source-detector compound. The scanner device ROFEX was developed manufactured and commissioned recently at FZD and allows scanning of objects...
Electrical resistance tomography (ERT) aims to estimate the electrical properties at the interior of an object from current-voltage measurements on its boundary. Although two-dimensional model is commonly used in most research, it cannot satisfy practical needs. In this paper, three different electrode structures in three-dimension (3D) were proposed and compared. An advanced version of the conjugate...
Electrical capacitance tomography (ECT) is gaining acceptance as a laboratory and industry tool to analyze gas/liquid two phase flow. To overcome the shortcomings of the existing analogue ECT system, a new 16-electrode digital electrical capacitance tomography system based on FPGA and DSP is designed. The new scheme can easily realize single frequency and multi-frequency excitation and demodulation...
Calderon's method was introduced to electrical capacitance tomography with square sensor in this paper. It is a direct algorithm of the image reconstruction, as no matrix inversion or iterative process is needed. It was implemented through numerical integration. Since the Gauss-Legendre quadrature was applied and can be predetermined, the image reconstruction process was fast and resulted in images...
Stirred vessels in the chemical process industry are largely devoid of instrumentation, which can visualise the internal concentrations and phase distribution. An electrical resistance tomography (ERT) system installed on a 1 metre/1 tonne scale pilot plant vessel is described. Some earlier applications showing how fluid mixing and precipitation can be imaged in time and space using solid-body graphics...
Electrical tomography has demonstrated the fast estimation of spatial distributions in a range of industrial processes, but has limitations in applications which feature multiple components. There is a need to discriminate between such components, or to identify specific materials, while retaining fast performance to permit the tracking of process dynamics. To deliver this need a method is outlined...
In order to detect geological bodies which harm to the safety production of mine, such as faultage, fold, coal bed attenuation region, falling post and so on, a resistivity tomography instrument is developed according to the requirement of explode-proof requirements. The potential channel and the current channel of the instrument are independent, and each channel has two grade active low-pass filter...
This paper presents a novel method to increase the signal to noise ratio in MIT data acquisition by exploiting transient process analysis. In front-end circuits for inductance measurements in MIT, a critical step is the phase sensitive demodulation, which includes a low pass filter. When the excitation source is switched from one coil to the next, a transient process occurs as the received voltage...
One channel capacitance tomograph was described. Its modular design gives the opportunity to test different measurement circuits. Described tomograph use measurement circuit based on CDC (Capacitance-to-Digital Converter). Control unit of the tomograph was implemented inside FPGA as a microprocessor system with hardware implementation of image reconstruction algorithm. The Landweber iterative image...
Fluidised beds are widely used in the pharmaceutical industry for granulation, drying and coating. The product quality strongly depends on the operation parameters and process conditions, e.g. inlet airflow rate, temperature and spraying flow rate. For granulation and drying processes, the flow conditions can change dramatically due to different moisture level, because of the change in physical characteristics...
This paper presents a design, implementation and performance of a novel data collection scheme for multi-channel impedance measurement, which is intended for developing high performance electrical tomography systems, even without parallel processing strategy. The hardware of electrical tomography employs electrical switching parts instead of mechanically moving parts to implement object scanning,...
It is important to study the slug flow in a gas/liquid flow to achieve an in-depth understanding of the mixture flow and optimization of industrial processes. This paper presents a study of the slug flow measurement in gas/liquid flow of horizontal pipe. The application of ERT for slug flow measurement is demonstrated and described, including the visualization of slug size and shape. A novel method...
This paper deals with the inverse scattering of ultra wide band (UWB) tomography used in reconstruction the dialectic properties of the unknown targets in 2D. The image reconstruction algorithm is based on the gradient minimization of an augmented cost function defined as the different between measured and calculated fields. The computation requires two successive steps: (i) direct and (ii) adjoint...
Electrical capacitance tomography (ECT) and electrical resistance tomography (ERT) have been developed separately as non-intrusive and/or non-invasive imaging techniques in the past. One of their applications is to measure multi-phase flows. The conventional ECT and ERT modalities are implemented individually. While ECT can be used to visualise permittivity distributions and ERT to visualise conductivity...
Electrical capacitance tomography (ECT) is fast, non-invasive and low cost imaging technique but offers very low spatial resolution. This paper presents the results of application of a nonlinear optimization technique for 2D reconstruction of images of complex objects. The iterative image reconstruction algorithm is based on the modified Levenberg-Marquard formula with additional convergence parameter...
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