QUALITATIVE EVALUATION OF AN INDUSTRIAL X-RAY COMPUTED TOMOGRAPHY SYSTEM
The invention of Computed Tomography (CT) has long been used for medical applications and material inspection. X-Ray Computed Tomography is a powerful imaging technique for viewing the interior of an object as if it had been sliced open along the image plane for viewing. The application of CT techniques has increasingly broadened in various industries i.e. aerospace, geoscience and archaeology. Malaysian Nuclear Agency has designed and developed an Industrial X-Ray CT system. The system consists of a 160 kV X-ray machine, a motorised linear rotary table, and X-scan linear array detector. 2-D CT image was acquired through the fan beam imaging modality. However, an X-ray CT does not provide information on the accuracy of the samples dimension and defects in terms of SI units. Another problems related to CT imaging is the alignment of X-ray fan beam with linear array detector (LAD) and formation of ring artifacts. In this work, methods for reducing ring artifacts are investigated like recalibrating the CT devices and ring filter application from CT reconstruction software. The alignment of X-ray fan beam with LAD by using dark films and VISI-X are described. Then, the dimension of CT sample can be estimated by calculating the geometrical magnification. The accuracy of geometrical magnification in estimating the size of CT sample is investigated by making a comparison with the measured magnification with varying position from X-ray source. Magnification is calculated by dividing the size of reconstructed CT sample with the measured size of actual CT sample.