Comparison of different benchmark particle size distributions

The benchmark of particle size measurement refers to the quantity directly measured by the testing method used, including number, length, area, volume and weight, etc. The particle size distribution values obtained from different benchmarks vary greatly. An article published in "New Scientist" magazine on October 13, 1991 stated that there are a large number of man-made objects in space orbiting the earth. When scientists regularly track them, they divide them into three groups according to size (see The following table). Among them, the percentage calculated based on quantity (third column), 0.1-1cm particles accounted for 99.3%; the percentage calculated based on volume (fourth column), the content of large particles accounted for 99.96%. It can be seen that the average diameter of the quantity distribution and volume of the same sample is 50cm, and it can be seen that the average diameter of different benchmarks is also very different. Therefore, they characterize sample characteristics from different perspectives.