METHOD AND DEVICE FOR MEASURING COARSE PARTICLE

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 【課題】従来よりも高い精度で、粉体中に低頻度に存在する所定の粒子径以上の粒子数と粒子の数を測定する粗大粒子の測定方法および粗大粒子の測定装置を提供する。【解決手段】粉体中の所定の粒子径以上の粒子の粒子数と数を測定する測定方法では、表面に粒子がある基材の撮影範囲と複数の撮影領域を一部を重ねて設定し、各撮影領域の撮影画像を得る。撮影画像において基材表面の色と粒子の色を抽出する。色抽出結果に基づき欠損して撮影された粒子を取り除き、粒子の像を少なくとも２階調の多階調処理を行う。粒子の多階調像に基づき輪郭を抽出し、粒子の輪郭画像を得る。粒子の輪郭画像に基づき粒子の重心位置の撮影範囲における座標を求め、粒子の像の位置を特定する。粒子の像の位置に基づき重複して撮影された粒子を１つの粒子に集約する。粒子の輪郭画像から粒子の粒子径を求め、所定の粒子径以上の粒子の重心位置に基づき粒子の数を数える。【選択図】図１