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-Experimental studies have been carried out to study the principle operation of the conductive type wire-mesh tomography sensor and analyse the wire-mesh tomography sensor for the liquid/gas two-phase flow interface and void fraction distribution in a process column. The measurement of the two-phase flows in the process column is based on the cross-sectional local instantaneous conductivity. The sensor consists of two planes of parallel electrode wires with 16 electrodes each and was placed orthogonally with each plane. The sensor electrode wires were made of tinned copper wire with an outer diameter of 0.91 mm which stretched over the sensor fixture. Therefore, this result in the mesh grid size with 5.53×5.53mm 2 . The wire-mesh sensor was tested in a horizontal liquid/gas two-phase flows process column with nominal diameter of 95.6 mm and the sampling frequency of 5882.3529 Hz. The tomogram results show that the wire-mesh tomography provides significant results to represent the void fraction distribution in the process column and estimation error was found in the liquid/gas interface level.

<span>Process of conveying liquid substance via the pipeline is the most common practice of transferring the liquid from one point to another point. Composite pipeline is becoming an option for liquid conveying purposed (instead of PVC, acrylic or metal) for its durability, longer lifetime and non-corrosive material in comparison with current pipeline. In order to ensure, the conveying process has a smooth flow rate without particle or bubble disturbance that could hinder good process flow, non-invasive monitoring system is always required. The ultrasonic measuring system is one of the monitoring options that could be applied. With proper designed for transmitting and conditioning circuitry, 300 kHz ultrasonic frequencies are found as the optimal frequency needed to penetrate across the composite pipeline with full of liquid. The ultrasonic sensor response is being successfully differentiated between full flow (no material blockage) and with bulk material blockage (dry and wet sand).</span>

Kertas kerja ini membincangkan algoritma alih yang digunakan dalam sistem tomografi optik. Sistem pengukuran terdiri daripada dua tatasusunan ortagon berjumlah 20 penderia optik. Masalah depan dimodelkan dengan menentukan pekali pelemahan optik bagi setiap piksel. Kemudiannya prinsip Lambert–Beer digunakan. Bagi masalah kebelakang sensitiviti matrik alih digunakan bagi mendapatkan pekali pelemahan optik bagi setiap piksel. Kata kunci: Algoritma alih, tomografi optik, buih This paper describes a transpose algorithm for use with an optical tomography system. The measurement system consisted of two orthogonal arrays, each having ten parallel views, resulting in a total of twenty sensors. The measurement section is divided into hundred equi–sized pixels. The forward problem is modelled by allocating an optical attenuation coefficient to each pixel. The attenuation of incident collimated light beams is then modelled using the Lambert–Beer law. The inverse problem is defined and the transpose of the sensitivity matrix is used to obtain an estimate of the attenuation coefficients in each pixel. The iterative method is investigated as a means of improving reconstructed image quality. Key words: Transponse algorithms, optical tomography, bubbles

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