工业CT探测尺寸误差的校准及误差分析

摘要

针对工业CT探测尺寸误差的校准需求，提出一套基于标准球的校准工业CT探测尺寸误差的方法，并对引起探测尺寸误差的各种因素进行了详细分析。首先使用中国计量科学研究院标准测长机对标准球的直径进行校准，再使用标定后的标准球校准工业CT探测尺寸误差。实验结果表明球标准器能够满足工业CT探测尺寸误差校准的需求，既能被精密校准，又可在工业CT中获得低伪像的高质量图像，从而实现对工业CT探测尺寸误差的校准。通过对影响工业CT探测尺寸误差因素的分析，讨论了工业CT成像过程中各环节的误差源，对于建立工业CT测量系统全面的校准方法和溯源具有重要意义。%According to the needs of calibrating the probing size error,a method based on the standard balls for the calibration of industrial CT probing size error is proposed and factors which cause the probing size error are detailly analyzed. Firstly,it calibrates the diameter by the length-measuring machine of National Institute of Metrology,then calibrates the industrial CT probing size error by these balls. The experimental results show that these standard balls can be calibrated accurately,and high quality image with lower artifacts can be acquired. And this kind of standards can meet the calibration needs of probing size error of industrial CT system. Error sources in imaging process,which influence the probing size error are discussed and analyzed. It is of great significance to establish calibration and traceability method for industrial CT system.