| 摘要 |
PURPOSE:To automatically and precisely measure the grain-size distribution of particles contained in a medium in one measurement without a preliminary measurement by detecting in order the number of the particles settling in the medium at a specified horizontal position every given time-interval. CONSTITUTION:An image at a detecting position h by a microscope 3 is converted into an image electric-signal S1 by a pickup tube 4, and a signal S2 of the particle number n is sent from a signal processing unit 5 to a memory and operation unit 6. The operation is continued at given time-intervals during sedimentation, and the obtained data are put in the block 6. The block 6 automatically calculates and memorizes the particle number, making the average particle-number of 250 for several seconds in the beginning of the sedimentation into a reference value, and the numbers of 10-90% of the value into nine distribution reference-values U10- U90. For example, the sedimentation time of 5.5 seconds corresponding to the particle number closest to U90=225 is calculated by the block 6 to obtain a particle diameter of 20mum, showing that particles smaller than 20mum exist 90%. |
