Evaluating X Ray Beam Hardening Corrections in Dense Optical Polymers
Resin-specific polynomial linearization suppresses computed tomography cupping artifacts in dense optical polymers while preserving inline cycle times.
Sphere Distance Error
Meaning
Metric quantifying the deviation between the measured and actual distance between the centers of two precision spheres assesses the spatial accuracy of a coordinate measuring machine. Identifying the sphere distance error allows a technician to pinpoint mechanical misalignment or software scaling issues within a scanner. This measurement is a fundamental part of the acceptance testing for any new industrial computed tomography system.
It provides a single numerical value that represents the volumetric precision of the entire setup. This data is recorded in a formal report that stays with the machine for its entire service life to provide a history of its performance.
Spatial Accuracy
Calibration phantoms containing ruby or ceramic spheres are scanned at various orientations to map the performance of the detector and the rotation stage. When the sphere distance error exceeds the manufacturer’s specification, it indicates that the system requires physical adjustment or a new calibration of its geometry. This check is performed regularly to ensure that the machine remains capable of measuring parts to the required tolerances.
Measurement Deviation
Factors such as thermal expansion of the machine frame or vibrations in the production environment can contribute to inaccuracies in the final output. Monitoring the sphere distance error over time helps a facility manager predict when a system will need maintenance before it starts producing bad data. These trends are often tracked in a quality management system to demonstrate compliance with international standards.
Geometric Error
Distortions in the reconstructed volume can lead to a situation where a part appears larger or smaller than its true physical size. Correcting the sphere distance error involves updating the voxel size or the center of rotation parameters within the reconstruction software. By resolving these issues early, a company avoids the cost of re-scanning a large batch of components.