Spatial resolution of industrial CT indicates the ability to distinguish the minimum specific geo-metric details from CT images , which represents one of the most important parameters of measurement ca-pability assessment of an industrial CT .Spatial resolution of industrial CT demands calibration in order to enhance the measurement capability and image quality of industrial CT .Regarding this problem , a set of grid and cross resolution line pairs cards were designed and manufactured via lithography , and on that ba-sis, the 2D system spatial resolution was calibrated with specific image processing methods such as back-ground correction .Experimental results prove that this method can be applied to calibrating spatial reso-lution of industrial CT by calculation of system spatial resolution through modulation transfer function .At last, some issues on improving measurement accuracy were discussed .

针对微纳坐标测量机的高精度性能指标无法精确校准的问题,提出了一种间接校准的方案.使用量块及标准球板校准微纳坐标测量机的尺寸测量示值误差,用标准球校准仪器的探测误差.并对中国计量科学研究院的微纳坐标测量机进行了校准实验,实验结果表明,该仪器的尺寸测量示值误小于0.2 μm,探测误差仅为0.125μm,校准结果均优于仪器的最大允许误差,验证了校准方案的合理可行性.

An exploratory research on the length measuring error calibration of industrial CT is carried out to move forward on the traceability of industrial CT in dimensional measurement. The length measuring error of industrial CT can be classified to two types:sphere distance error and plane distance error. For the widely accepted sphere distance error,a tiny forest-ball is developed,and calibrated by a high precision coordinated measuring machin. Then the tiny forest-ball is used to calibrate an industrial CT called Metrotom 1500,the sphere distance error is smaller than ± 2 μm,and smaller than the maximum permissible error of this machine. For the plane distance error,an exploratory experiment is conducted with steel gauge blocks and ceramic gauge blocks,and the plane distance error is out of the maximum permissible error. The experiment result shows that it is very different to calibrate the length measuring error of industrial CT by sphere distance and plane distance,and the plane distance error is much larger than sphere distance error when measuring a same length.

A small forest-ball was manufactured and calibrated using CMM F25. An industrial CT called Metrotom1500 was calibrated by the small forest-ball and another big forest-ball produced by Carl Zeiss. These two forest-balls were separately measured at two different magnifications of the industrial CT, and the measurement results could meet the maximum permissible error of Metrotom1500.

工业CT以其出色的内部成像能力，在无损检测领域发挥着越来越重要的作用。本文以某喷油器生产企业为案例，介绍了工业CT在喷油器故障检测上的应用。结果表明，通过工业CT的扫描成像，能够清晰地观察到喷油器的故障位置和原因。这一应用案例说明，工业CT在工业零部件的内部结构检测上有着巨大的应用前景，有待进一步的发掘。

介绍了相干扫描显微镜的测量原理.提出了使用经校准的碳化硅超光滑圆盘作为标准平面,校准相干扫描显微镜的测量噪声和残余平面度特性.其中测量噪声通过先重复测量标准平面同一位置的表面形貌图,再使用相减法处理得到;残余平面度通过先多次重复测量标准平面不同位置的表面形貌图,再使用阈值法处理得到.最后基于此方法对中国计量科学研究院的相干扫描显微镜进行了校准实验,结果表明:使用1次相减法即可校准测量噪声,残余平面度可通过在标准平面上不同位置处做10次以上重复测量并求其平均形貌来校准.

Similar to traditional CMM, probing error of industrial CT is used for assessing the 3D measurement error of the machine in a very small measurement volume. A research on the assessment of probing error of industrial CT is conducted here. Lots of assessment tests are carried out on the industrial CT Metrotom1500 in the National institute of metrology, using standard balls with different size and materials. The test results demonstrate that probing error of industrial CT can be affected seriously by the measurement strategy and standard balls. According to some further analysis about the test results, the assessment strategy of industrial CT’s probing error is concluded preliminary, which can ensure the comparability of the assessment results in different industrial CT system.