Nondestructive inspection plays a key role in helping to investigate sensitive assembled components in 3D, such as our example of an analog pocket watch. Micro-CT scanning has even been used to investigate the internal mechanisms of a corroded, barnacle-covered pocket watch recovered from a 17th century shipwreck. For newly assembled components as well as archaeological finds, X-ray microscopy allows for the examination of assembled products in an as-manufactured state without worry of pieces shifting position during disassembly for a visual inspection.
X-Ray Microscopic Imaging of Assembled Devices
This month we imaged an analog watch using the SkyScan 1273 micro-CT, which was ideal because of the full 130 kV of X-ray energy available in the instrument. With the dense, primarily metal composition of the sample, higher X-ray energies are required to achieve a sufficient level of transmission through the sample to generate our final reconstructed dataset.
As shown in Figure 2, the SkyScan 1273 had enough X-ray flux at the isotropic voxel size of 15µm to generate a detailed image of the individual gears and components comprising the assembled watch.
Exploring the data in 3D allows us to move through the dataset visually and inspect the location and engagement of each component with one another (Figure 3). CTVox also allows us to customize our colors and shadowing to help produce color-similar renderings.
CTAnalyzer provides tools useful in isolating any individual component within the watch that we would like to examine in greater detail (Figure 4). Through use of custom VOI and segmentation tools, CTAn allowed us to extract the volume in the sample that corresponds to the gear connected to the winding spring. The winding spring is essential to the watch operation as it stores the potential energy in the watch after it is wound and slowly releases that energy as the watch ticks.
The ability to overlay datasets within CTVox that share a common coordinate system provides us with the opportunity to gain more context on the position of our isolated gear component within the larger watch assembly (Figure 5). As before, we can position the sample in any view useful to our examination of the watch components while exporting high resolution images and videos of the results.
Readers may want to compare this view of an analog watch with a previous scan we did of an Apple watch.
The high X-ray power (up to 39W) of the SkyScan 1273 was a perfect match for the dense analog watch examined in this study. The data were well resolved, allowing for isolated extraction of individual sub-components using CTAn.
We hope you found this Image of the Month informative and encourage you to subscribe to our newsletter and social media channels in preparation for the continuation of our Image of the Month series next month.
|Filter||2 mm Copper|
|Pixel Size (µm)||15|
|Exposure Time (ms)||900|
|Scan Time (HH:MM:SS)||09:56:22|
These scans were completed on our SkyScan 1273 micro-CT system at the Micro Photonics Imaging Laboratory in Allentown, PA. Reconstructions were completed using NRecon while visualization and volumetric inspection of the 2D and 3D results were completed using Dataviewer and CTVox. CTan was utilized to segment and isolate individual internal components of the dataset.
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