Feasibility of dimensional gauges made of plastic used for acceptance tests of coordinate measuring systems

Dimensional X-ray computed tomography systems (DXCT) having the capability of measuring sizes and geometrical features are paid attention as a new type of coordinate measuring systems (CMS). A gauge used for verifying the measurement performance of DXCT is demanded for made of the material having low X-ray attenuation coefficient. In this study, the plastic is proposed to be used as a material of the gauge and the suitability of that is investigated. The observation of long-term dimensional stability shows Poly Phenylene Sulfide (PPS) is the most stable material in the observed plastics. The evaluation of actual CTE of plastic and of calibration uncertainty is demonstrated. The test uncertainty of the performance test of a coordinate measuring system including DXCT was estimated. The estimated uncertainty leads the guideline of conditions to be considered when the performance of DXCT is evaluated using the gauges.