PARTICLE SIZE DISTRIBUTION MEASUREMENT APPARATUS AND PARTICLE SIZE DISTRIBUTION MEASUREMENT METHOD

To correctly calculate a particle size accumulation curve of a granular material while reducing the facility cost and work time.SOLUTION: A particle size distribution measurement apparatus calculates in a pixel unit an area of a target on the basis of image data of the target obtained by imaging the target in the known outer size by an imaging unit 14 in such a state that the target is installed at the substantially same position as the position of a mounting surface part 12 with respect to the imaging unit 14, obtains a calibration factor α being the actual size per a pixel from the area in a pixel unit of the target and the outer size of the target, obtains a first granular material area in which the projection area of each granular material 2 is calculated in a pixel unit on the basis of contour data of each granular material 2, obtains a second granular material area being the projection area of each granular material 2 in a real space by multiplying the first granular material area by the square α2 of the calibration factor α as the area per pixel, and calculates the particle size D of each granular material 2 on the basis of the second granular material area.SELECTED DRAWING: Figure 5 【課題】設備コストおよび作業時間の低減を図りつつ粒状材の粒径加積曲線を正確に算出する。【解決手段】外形寸法が既知のターゲットを、撮像部１４に対する載置面部１２の位置とほぼ同じ位置に設置した状態で撮像部１４により撮像して得たターゲットの画像データに基づいてターゲットの面積をピクセル単位で算出し、ターゲットの外形寸法およびターゲットのピクセル単位の面積からピクセル当たりの実寸法である校正係数αを求め、各粒状材２の輪郭データに基づいて各粒状材２の投影面積をピクセル単位で算出した第１の粒状材面積を求め、第１の粒状材面積に校正係数αの二乗α２を１ピクセル当たりの面積として乗算することで実空間での各粒状材２の投影面積である第２の粒状材面積を求め、第２の粒状材面積に基づいて各粒状材２の粒径Ｄを算出する。【選択図】図５