密度分辨率是工业CT性能指标。在进行CT性能测试时, 液体密度差试件配制中必须考虑溶质的偏质量体积。指出GJB 5312标准描述的试样配制方法会造成实际密度差小于所给出的标称值, 使测得的密度分辨能力偏低。讨论了偏质量体积参数的计算方法和试样的配制方法。通过实例说明方法的正确性, 对改进GJB 5312标准提出了建议。

The mass density resolution is one of important characteristics of industrial CT(ICT). When the performance test for ICT density measurement was carried, the partial mass volume should be considered in the concoction of the liquid density phantom. This paper revealed the notable difference between the real density values of the phantom and the proposed values by the current standards GJB 5312. The calculation formula to overcome the partial mass volume effect was given, and the concocting method of liquid density phantom was proposed. The precision of the method was demonstrated through a practical test example. The suggestion of modifying the current standards of ICT performance test was proposed.