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.
Step Wedge Calibration
Meaning
Standardized procedure using a block of material with varying thicknesses establishes the relationship between material depth and X-ray attenuation. Implementing step wedge calibration allows a facility to create a custom lookup table that converts pixel intensity into actual physical thickness. This ensures that the results of a scan are consistent even if the X-ray tube’s power varies slightly over time.
Most laboratories perform this check at the start of every shift to maintain the highest level of accuracy. It is a fundamental part of the quality control process for both digital and film radiography.
Density Reference
Comparing the intensity values of a known material to a set of steps provides a baseline for all subsequent scans. Step wedge calibration is especially important when the part being inspected has a wide range of thicknesses that must all be measured in a single exposure. This process allows the software to compensate for the non-linear absorption of energy as the beam passes through the object.
Attenuation Mapping
Creating a map of how different materials block radiation is the primary goal of the calibration process. By using a step wedge calibration, a technician can identify the exact point where the detector becomes saturated or the signal becomes too weak. This knowledge is used to set the optimal exposure parameters for every new part that enters the factory.
Calibration Reliability
Maintaining a record of these daily checks is a requirement for many international safety standards. A successful step wedge calibration proves that the imaging system is operating within its specified limits and that the data it produces is trustworthy. This documentation is often the first thing reviewed during a regular audit of the manufacturing facility.