YU Ze-li,FANG Yong-qiang,YANG Jun-hong,ZHANG Bing,ZHANG Yi-xin,ZHENG Yi,BI Ge-ping
Distortion can reflect the deviation between the actual image and the ideal image of a metallographic microscope, and is an important technical indicator for accurate and reliable performance of metallographic microscopes. According to the calibration standard "Evaluation and Representation of Measurement Uncertainty", the distortion measurement process of the metallographic microscope was studied, the mathematical model for the uncertainty evaluation of the distortion measurement results was established, the sources of uncertainty were comprehensively analyzed, and the uncertainty of the distortion measurement results of the metallographic microscope was evaluated.The results show that when the coverage factor k=2, the confidence level is 95%, under the condition of the total magnifications is 50×, 100×, 200×, 500× and 1000×, the relative distortion measurement results of the metallographic microscope is (0.5±0.4)%, (0.3±0.6)%, (1.3±0.4)%, (0.4±0.4)%, (0.9±0.1)%, respectively. The uncertainty of the measurement results mainly comes from the distortion measurement system and repeatability test.