Uncertainty Evaluation on Average Intercept of Metal Grain Detected by Optical Microscope

According to JJF 1059-1999 and GB/T 6394-2002, using an optical microscope and metallographic image analysis software to observe and measure the plane of steel grain, under 200 times magnification observation, the method of straight-line basis over cut-off point was used to analyze the measurement uncertainty sources of average intercept of metal grains, and each component of uncertainty was assessed, the final report of expanded uncertainty of measurement results was obtained. The results showed that the measurement uncertainty results of average grain intercept of steel grain were reported as the average intercept measurement value (23.7±0.6) μm, k=2.