论文部分内容阅读
介绍了如何制作品粒度投影屏来改进传统的比较评级法,使能直接在投影屏上进行对照评级以提高其精度,同时亦可用于多人观察讨论和方便教学。
This paper introduces how to make the particle size projection screen to improve the traditional comparative grading method, which can directly compare the grading on the projection screen to improve its accuracy. At the same time, it can also be used to observe and facilitate teaching.