Assessment of the Measurement Procedure for Dimensional Metrology with X-ray Computed Tomography
Assessment of the Measurement Procedure for Dimensional Metrology with X-ray Computed Tomography
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DOI：
10.1016/j.procir.2016.02.018
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
A. Kraemer;G. Lanza
中科院分区：
文献类型：
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作者：
A. Kraemer;G. Lanza
X射线计算机断层扫描（CT）是一种很有前途的技术，用于工业零件的质量保证。然而，用于尺寸计量的计算机断层扫描是一个复杂的间接测量过程，其结果取决于各种影响因素。为了确保测量可追溯到基本SI单位，必须与实际测量结果一起给出有关测量不确定度的声明。一种普遍接受的不确定度评估方法是使用校准工件。然而，在整个测量过程中，导致不确定度的影响因素没有单独量化，并且仍然未知。测量的质量和可靠性（以测量不确定度表示）取决于硬件和软件以及用户设置的扫描参数。不仅扫描参数，如电流，管电压或曝光时间，可以影响测量结果，而且表面测定和测量功能的几何评价增加了测量不确定度，在这方面的贡献，测量过程中的CT评估和影响因素，在整个测量过程中的不同步骤被确定以及量化。该方法用于分析测试对象的不同测量的数据质量。将CT数据与物体的触觉校准数据进行比较，并给出实验不确定度评估。
X-ray computed tomography (CT) is a promising technology for quality assurance of industrial parts. However, computed tomography for dimensional metrology is a complex and indirect measurement procedure, whose results depend on a variety of influencing factors. To ensure that a measurement is traceable back to the basic SI units, a statement about the measurement uncertainty has to be given together with the actual measurement result. A generally accepted method for uncertainty evaluation is the use of calibrated workpieces. However, the influencing factors throughout the measurement procedure that contribute to the uncertainty are not quantified individually and remain unknown. The quality and reliability of the measurement, expressed in measurement uncertainty, hereby depends on hard- and software as well as user-set scan parameters. Not only scan parameters, such as current, tube voltage or exposure time, can influence the measurement results, but also surface determination and geometrical evaluation of the measured features add to the measurement uncertainty.In this contribution, the measurement procedure for metrological computed tomography is assessed and influencing factors throughout the different steps in the measurement procedure are identified as well as quantified. The approach is used to analyze the data quality of different measurements with a test object. The CT data are compared to tactile calibration data of the object and an experimental uncertainty evaluation is given.