New Concept for Detail Sensitivity Monitoring in industrial Computed Tomography - the EURAMET Project SensMonCT

Digital X-Ray Imaging and Computed Tomography (CT) are applied in industry for flaw detection, flaw evaluation and dimensional measurement. This requires correct experimental system settings for sufficient visibility and detectability of flaws and structure elements. A new parameter, the Detail Detection Sensitivity (DDS), is introduced. A related standard draft (WK84836-24) has been submitted to the ASTM E07 committee. The ASTM guide E 1441 [1] describes three essential functions for the characterisation of iCT systems. These are the Contrast Discrimination Function (CDF), the MTF, and the Contrast Detail Diagram (CDD). The related procedures and formulas for the determination of these functions and the DDS will be discussed, based on measurements of newly developed test gauges with holes of different diameters with Industrial Computed Tomography systems (iCT) and by modelling. Currently, the DDS of iCT systems is evaluated by human operators which is unreliable and costly. Therefore, within the EURAMET project "SensMonCT" new test gauges and traceable automated measurement and monitoring methods will be developed and procedures to evaluate the DDS of iCT systems and its standardisation.