Optimising XCT acquisition speed for image quality and dimensional measurements - PhDData

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Optimising XCT acquisition speed for image quality and dimensional measurements

The thesis was published by Zwanenburg, E. A., in January 2022, University of Warwick.

Abstract:

Acquisition speed is an important consideration for the use of XCT in industry and research applications. A literature review to examine the acquisition parameters with the greatest impact on the speed showed that authors typically use a lower number of projections in faster XCT.

The operator and their acquisition parameter selection have a significant impact on the resulting image quality. Different image quality metrics have been used to access acquisition parameters among which, for the first time, anisotropy. For CFRPs a low voltage and a long SDD provided the best contrast between the polymer and the resin, which have very similar absorption coefficients. The effect of acquisition parameters on image quality metrics and dimensional measurements was investigated; anisotropy and SNR showed a better correlation to the dimensional measurements than the other investigated parameters. There is no significant measurement improvement when increasing the number of projections or the averages and reducing the projections or binning minimally affected the measurement accuracy.

The current standard of measurement obtained with XCT and scanning practices were investigated by a round robin studies on metrology systems and a comparison between a metrology and non-metrology XCT system was made. For the first time systems have been compared using the same objects. The results showed that all tested metrology XCT systems were capable to achieve sub-voxel measurements but their MPE statements were too tight. The comparison between the metrology and non-metrology XCT systems showed applying voxel scaling makes the results comparable to metrology graded systems especially for larger magnifications (



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