The measuring method and measurement device of the oversize grain of oversize grain

摘要

PROBLEM TO BE SOLVED: To provide a method and device for measuring coarse particles, capable of measuring the particle size and number of particles existing at a low frequency in a powder and having a particle size equal to or more than a predetermined particle size with accuracy higher than ever before.SOLUTION: The measurement method for measuring the particle size and number of particles existing at a low frequency in a powder and having a particle size equal to or more than a predetermined particle size comprises: partially superimposing and setting an imaging range and a plurality of imaging regions of a base material having particles on the surface to obtain an imaged image of each imaging region; extracting the color of the base material surface and the color of particles in the imaged image; removing particles lost and imaged on the basis of the color extraction result to subject the image of particles to multi-gradation having at least two-gradation; extracting an outline on the basis of the multi-gradation image of the particles to obtain the outline image of the particles; calculating a coordinate of the centroid position of the particles in the imaging range on the basis of the outline image of the particles to specify a position of the image of the particles; collecting the particles doubly imaged into one particle on the basis of the position of the image of the particles; and calculating the particle size of the particles from the outline image of the particles to count the number of the particles on the basis of the centroid position of the particles having a particle size equal to or more than a predetermined particle size.SELECTED DRAWING: Figure 1