Realisation of a metrological characteristics approach to calibration of X-ray computed tomography
X-ray computed tomography (XCT) is increasingly being applied for coordinate measurement of complex three-dimensional manufactured components. XCT is especially attractive for components that result from laser powder bed additive processes, as internal features, e.g. porosity or cooling channels, can be measured. For XCT to be applied in quality control scenarios, its capabilities need to be quantified through calibration, yet no calibration process has been developed to date. ISO committee 213 is developing specification standards for performance verification, but n- ot for calibration. The student will investigate an approach to calibration that has been applied to the optical measurement of surface topography, using the concept of “metrological characteristics”. These are characteristics of an instrument that can be determined and then used as the standard uncertainty terms in a given measurement model for a given task. The trick is to define a small number of metrological characteristics that can be determined and which capture the multitude of influence factors that contribute to the measurement uncertainty for XCT. To add to this, the characteristics need to be simple to determine, with cost-effective material measures and in an industrial setting. Such a calibration framework may not be completely rigorous (e.g. some influence factors will be contributing more than once to the final uncertainty statement), but it is a well-needed starting position and the tolerances required in additive manufacturing are not generally as high as those in conventional manufacturing.
We seek an excellent student to join the world-leading teams at University of Nottingham and the Manufacturing Technology Centre.
The project will be supervised by Professor Richard Leach, from the Manufacturing Metrology Team, see www.nottingham.ac.uk/research/manufacturing-metrology
How to apply:
Please send a copy of your covering letter, CV and academic transcripts to [Email Address Removed]. Please note, applications without academic transcripts will not be considered.
• Due to funding restrictions, the position is only available for UK or EU candidates
• Candidates must possess or expect to obtain, a high 2:1 or 1st class degree in Engineering, Physics, or other relevant discipline.