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.
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.