scholarly journals Effects of off-focal radiation on dimensional measurements in industrial cone-beam micro-focus X-ray computed tomography systems

2020 ◽  
Vol 66 ◽  
pp. 472-481
Author(s):  
Nadia Flay ◽  
Stephen Brown ◽  
Wenjuan Sun ◽  
Thomas Blumensath ◽  
Rong Su
Keyword(s):  
Computed Tomography ◽  
Cone Beam ◽  
X Ray ◽  
Dimensional Measurements ◽  
X Ray Computed

scholarly journals Automated evaluation of the surface point quality in dimensional X-ray computed tomography

2020 ◽  
Vol 87 (2) ◽  
pp. 111-121 ◽  
Author(s):  
Andreas Michael Müller ◽  
Lorenz Butzhammer ◽  
Florian Wohlgemuth ◽  
Tino Hausotte
Keyword(s):  
Computed Tomography ◽  
Surface Point ◽  
Random Measurement Error ◽  
X Ray ◽  
Random Measurement ◽  
Automated Evaluation ◽  
Dimensional Measurements ◽  
X Ray Computed ◽  
Model Measurement

AbstractX-ray computed tomography (CT) enables dimensional measurements of numerous measurands with a single scan, including the measurement of inner structures. However, measurement artefacts complicate the applicability of the technology in some cases. This paper presents a methodology to assess the surface point quality of computed tomography measurements without the requirement of a CAD model. Measurement artefacts lowering the surface point quality can therefore automatically be detected. The correlation of quality values with the random measurement error is demonstrated. The presented method can in principle be used to weight single fit points to reduce the measurement uncertainty of CT measurements.

Automatic Knot Detection in Coarse-Resolution Cone-Beam Computed Tomography Images of Softwood Logs

2019 ◽  
Vol 69 (3) ◽  
pp. 185-187
Author(s):  
Magnus Fredriksson ◽  
Julie Cool ◽  
Stavros Avramidis
Keyword(s):  
Computed Tomography ◽  
Exploratory Study ◽  
Ct Scanning ◽  
Detection Algorithm ◽  
Cone Beam ◽  
X Ray ◽  
Coarse Resolution ◽  
Computed Tomography Images ◽  
X Ray Computed ◽  
Accurate Position

Abstract X-ray computed tomography (CT) scanning of sawmill logs is associated with costly and complex machines. An alternative scanning solution was developed, but its data have not been evaluated regarding detection of internal features. In this exploratory study, a knot detection algorithm was applied to images of four logs to evaluate its performance in terms of knot position and size. The results were a detection rate of 67 percent, accurate position, and inaccurate size. Although the sample size was small, it was concluded that automatic knot detection in coarse resolution CT images of softwoods is feasible, albeit for knots of sufficient size.

scholarly journals OBSERVATIONS ON THE PERFORMANCE OF X-RAY COMPUTED TOMOGRAPHY FOR DIMENSIONAL METROLOGY

2016 ◽  
Vol XLI-B5 ◽  
pp. 25-31
Author(s):  
H. C. Corcoran ◽  
S. B. Brown ◽  
S. Robson ◽  
R. D. Speller ◽  
M. B. McCarthy
Keyword(s):  
Computed Tomography ◽  
Reverse Engineering ◽  
X Rays ◽  
Dimensional Metrology ◽  
Beam Hardening ◽  
X Ray ◽  
Accuracy And Precision ◽  
Dimensional Measurements ◽  
X Ray Computed

X-ray computed tomography (XCT) is a rising technology within many industries and sectors with a demand for dimensional metrology, defect, void analysis and reverse engineering. There are many variables that can affect the dimensional metrology of objects imaged using XCT, this paper focusses on the effects of beam hardening due to the orientation of the workpiece, in this case a holeplate, and the volume of material the X-rays travel through. Measurements discussed include unidirectional and bidirectional dimensions, radii of cylinders, fit point deviations of the fitted shapes and cylindricity. Results indicate that accuracy and precision of these dimensional measurements are affected in varying amounts, both by the amount of material the X-rays have travelled through and the orientation of the object.

High resolution cone beam X-ray computed tomography of 3D-microstructures of cast Al-alloys

2011 ◽  
Vol 62 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Johann Kastner ◽  
Bernhard Harrer ◽  
H. Peter Degischer
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Al Alloys ◽  
Cone Beam ◽  
X Ray ◽  
X Ray Computed

scholarly journals Monte Carlo evaluation of glandular dose in cone-beam X-ray computed tomography dedicated to the breast: Homogeneous and heterogeneous breast models

2018 ◽  
Vol 51 ◽  
pp. 99-107 ◽  
Author(s):  
Antonio Sarno ◽  
Giovanni Mettivier ◽  
Raffaele M. Tucciariello ◽  
Kristina Bliznakova ◽  
John M. Boone ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Monte Carlo ◽  
Cone Beam ◽  
X Ray ◽  
X Ray Computed ◽  
Monte Carlo Evaluation

Development of Dimensional X-Ray Computed Tomography

2015 ◽  
Vol 9 (5) ◽  
pp. 567-571 ◽  
Author(s):  
Hiroyuki Fujimoto ◽  
◽  
Makoto Abe ◽  
Sonko Osawa ◽  
Osamu Sato ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coordinate Measuring Machine ◽  
National Metrology Institute ◽  
Maximum Deviation ◽  
Dimensional Metrology ◽  
X Ray ◽  
Tomography System ◽  
Dimensional Measurements ◽  
X Ray Computed ◽  
Measuring Machine

Recently, a strong need has arisen for a dimensional X-ray computed tomography system that is capable of dimensional measurements. This is because the speedy realization of dimensional measurements for outward forms and inward forms on dense spatial points remarkably simplifies and accelerates production loop. However, although the image obtained via XCT describes the structure clearly and in great detail, dimensional metrology by means of XCT is not simple. The National Metrology Institute of Japan has been carrying out performance tests using gauges that include the gauges proposed in ISO10360. In this work, the magnification variation correction is carefully presented, and a maximum deviation of less than 5 μm is shown to be possible by means of the measurement of the forest phantom of 27 ruby spheres, the locations of which are calibrated by the coordinate measuring machine.

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