scholarly journals Reference object for evaluating the accuracy of porosity measurements by X-ray computed tomography

2016 ◽  
Vol 6 ◽  
pp. 122-127 ◽  
Author(s):  
Petr Hermanek ◽  
Simone Carmignato
Keyword(s):  
Computed Tomography ◽  
Reference Object ◽  
X Ray ◽  
X Ray Computed ◽  
Porosity Measurements

scholarly journals High-resolution imaging of depth filter structures using X-ray computed tomography

2021 ◽  
Author(s):  
T. F. Johnson ◽  
F. Iacoviello ◽  
J. H. Welsh ◽  
P. R. Shearing ◽  
D. G. Bracewell
Keyword(s):  
Computed Tomography ◽  
Flow Simulation ◽  
Pixel Size ◽  
Average Pore ◽  
X Ray ◽  
Average Porosity ◽  
X Ray Computed ◽  
Resolution Imaging ◽  
Filter Structures ◽  
Porosity Measurements

AbstractA multiple length scale approach to the imaging and measurement of depth filters using X-ray computed tomography is described. Three different filter grades of varying nominal retention ratings were visualized in 3D and compared quantitatively based on porosity, pore size and tortuosity. Positional based analysis within the filters revealed greater voidage and average pore sizes in the upstream quartile before reducing progressively through the filter from the center to the downstream quartile, with these results visually supported by voidage distance maps in each case. Flow simulation to display tortuous paths that flow may take through internal voidage were examined.Digital reconstructions were capable of identifying individual constituents of voidage, cellulose and perlite inside each depth filter grade, with elemental analysis on upstream and downstream surfaces confirming perlite presence. Achieving an appropriate pixel size was of particular importance when optimizing imaging conditions for all grades examined. A 3 µm pixel size was capable of representing internal macropores of each filter structure; however, for the finest grade, an improvement to a 1 µm pixel size was required in order to resolve micropores and small perlite shards. Enhancing the pixel size resulted in average porosity measurements of 70% to 80% for all grades. Graphical abstract

scholarly journals High-resolution imaging of depth filter structures using X-ray computed tomography

2021 ◽  
Author(s):  
Thomas Johnson ◽  
Francesco Iacoviello ◽  
John Welsh ◽  
Paul Shearing ◽  
Daniel Bracewell
Keyword(s):  
Computed Tomography ◽  
Flow Simulation ◽  
Pixel Size ◽  
Average Pore ◽  
X Ray ◽  
Average Porosity ◽  
X Ray Computed ◽  
Resolution Imaging ◽  
Filter Structures ◽  
Porosity Measurements

A multiple length scale approach to the imaging and measurement of depth filters using X-ray computed tomography is described. Three different filter grades of varying nominal retention ratings were visualized in 3D and compared quantitatively based on porosity, pore size and tortuosity. Positional based analysis within the filters revealed greater voidage and larger average pore sizes in the upstream quartile before reducing progressively through the filter from the center to the downstream quartile, with these results visually supported by voidage distance maps in each case. Flow simulation to display tortuous paths that flow may take through internal voidage were examined. Digital reconstructions were capable of identifying individual constituents of voidage, cellulose and perlite inside each depth filter grade, with elemental analysis on upstream and downstream surfaces confirming perlite presence. Achieving an appropriate pixel size was of particular importance when optimizing imaging conditions for all grades examined. A 3 µm pixel size was capable of representing internal macropores of each filter structure, however for the finest grade an improvement to a 1 µm pixel size was required in order to resolve micropores and small perlite shards. Enhancing pixel size resulted in average porosity measurements of 70% to 80% for all grades.

Traceable Porosity Measurements in Industrial Components Using X-Ray Computed Tomography

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Petr Hermanek ◽  
Filippo Zanini ◽  
Simone Carmignato
Keyword(s):  
Computed Tomography ◽  
Optimization Method ◽  
Reference Object ◽  
Void Content ◽  
Industrial Case Study ◽  
X Ray ◽  
Internal Porosity ◽  
Improve Measurement ◽  
X Ray Computed ◽  
Manufacturing Technologies

Manufacturing technologies deliver products that can suffer from various defects, one of which is internal porosity. Pores are present in most of the parts produced by, e.g., casting, additive manufacturing, and injection molding and can significantly affect the performance of the final products. Due to technological and economic limits, typically porosity cannot be completely removed by optimizing process parameters. It is therefore essential to have a measurement technique that can detect and evaluate these defects accurately. Apart from conventional nondestructive techniques, such as ultrasonic testing or Archimedes’ method that suffer from various limitations, X-ray computed tomography has emerged as a promising solution capable of measuring size, spatial distribution, and shape of pores. In this paper, a method to achieve traceable computed tomography measurements of internal porosity using a reference object with calibrated internal artificial defects is described and demonstrated on an industrial case study. Furthermore, the possibility to improve measurement results by optimizing parameters used for the evaluation of acquired data is discussed. The optimization method is based on an iterative procedure that reduces to ±5 × 10−5 mm3 the error of the measured values of total void content in the reference object.

X-Ray Computed Tomography of Ultralightweight Metals

1999 ◽  
Vol 11 (1) ◽  
pp. 199-211
Author(s):  
J. M. Winter ◽  
R. E. Green ◽  
A. M. Waters ◽  
W. H. Green
Keyword(s):  
Computed Tomography ◽  
X Ray ◽  
X Ray Computed
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