Tomography is a method to capture a cross-sectional image based on the data obtained by sensors, distributed around the periphery of the analyzed system. Optical tomography is one of the tomography methods which are non-invasive and non-intrusive system, consisting of emitter with detectors. Combinations of Charge-Coupled Device and low intensity laser diode are used in this research. Experiments on air bubbles detecting in non-flowing crystal clear water are conducted. Cross-sectional image of two phase flow; air and liquid are captured using this optical hardware construction and the information on air diameter, shape and path are observed using LabVIEW programming. � 2017 UTHM Publisher. All right reserved.

This paper explains the front-end design for noninvasive electrical resistance tomography. The electrical resistance tomography system presented in this paper uses high-frequency potential. In this design, the phase-shift demodulation (PSD) approach was eliminated and replaced by a peak detector circuit. The switching between transmitter/receiver and the transmitting channel was controlled by an analogue switch, MAX319 and demultiplexer, DG406, respectively. A microcontroller was applied to the data acquisition which eliminates the needs of a data acquisition system. Sensor readings of each receiver from each transmitter groups were tested experimentally, compared and analysed with simulation results. These experimental readings were compared with the sensors reading simulated from COMSOL Multiphysics software. As a result, the current values between 0-1mA from experiments was similar with the simulation results for all groups of transmitters. Thus, it can be concluded that the front-end design can be applied for the non-invasive ERT when high frequency is considered. � 2018 Universiti Teknikal Malaysia Melaka. All rights reserved.

This research presents an application of Charge-Coupled Device (CCD) linear sensor and laser diode in an optical tomography system. Optical tomography is a non-invasive and non-intrusive method of capturing a cross-sectional image of multiphase flow. The measurements are based on the final light intensity received by the sensor and this approach is limited to detect solid objects only. The aim of this research is to analyse and demonstrate the capability of laser with a CCD in an optical tomography system for detecting objects with different clarity in crystal clear water. Experiments for detecting transparent objects were conducted. The object's diameter and image reconstruction can also be observed. As a conclusion, this research has successfully developed a non-intrusive and non-invasive optical tomography system that can detect objects in crystal clear water. � Penerbit UTHM.