Comparison of Accuracy Verification Method for X-Ray CT

X-ray computed tomography (X-ray CT) has been occupying indispensable position in geometrical and dimensional measurements in industry, which is capable of measuring both external and internal dimensions of industrial products. Since there have been no international standard for evaluating measuring performance of industrial X-ray CT, it is hard to compare the measurement accuracy of X-ray CT supplied by different manufacturers. Although evaluation procedures for conventional coordinate measuring machines (CMMs) have been proposed and standardized, they cannot be applied for X-ray CT as they are. A hole plate and a step cylinder are examined to see which is a more suitable material standard for evaluating the measurement performance of X-ray CT. Experimental result shows that the step cylinder reveals the effect of penetration length more apparently.