When exposing dispersed particles to laser light, the laser light is diffracted by the particles. By collecting this diffracted light with a lense, diffraction ring is shown on the focal plane. From analysis of the diameter of this diffraction ring and the light intensity distribution based on the Fraunhofer diffraction theory, particle size distribution can be obtained. This analysis using laser diffraction works only around 1μm. For that reason particles which diameter are under 1μm are analyzed by Mie scattering theory. They are detected by sensors for scattered lights, not by sensers for diffracted lights, to know particle size distribution.
We can measure difficult samples such as dusts in a suspension or oil when their particle sizes are within a range of measurement.
※One-shot measurement (dry) is also available for a very little amount of samples
Analyzer | LMS-3000, LMS-2000e |
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Measurement Range | 0.1μm-3500μm(1 range) |
Sample Amount | Wet: several grams, Dry: several ten grams |
Photo?extinction and?centrifugal sedimentation method uses Stokes' law that large particles settle out sooner than small particles if their specific gravities are the same. By analyzing the particle concentration at that time from turbidity change by light transmission, particle size distribution is obtained. With fine particles a centrifuge is used to shorten sedimentation time. ※For this measurement true specific gravity of powder is needed. We can also measure true specific gravity.
Analyzer | MPS-Z(SKC-2000S) |
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Measurement Range | 0.1μm~500μm(1 range) |
Sample Amount | Several grams |
Sonic wave sieving method is to vibrate only air on sieves in a closed space. Vibration of air gives powders on sieves cyclic vertical movement. Powders jump from sieves every half cycle and return to the sieves in the next half cycle. Some pass through the sieve openings and the others remain on the sieves. Mechanical pulses from the bottom of the sieves and in the vertical direction prevent adhesion and clogging.
Analyzer | RPS-105,L-200P |
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Measurement Range | 20μm-5600μm |
Sample Amount | Several ten grams or more |
Vibrating sieving method is to generate torsional vertical vibration by electromagnetic vibration to make powders turning on the sieves while sieving. It is more effective than general vibrating sieves. Wet sieving is also available.
※φ75, φ150 and φ200mm dia sieves can be used
Analyzer | Octagon Digital |
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Measurement Range | 20μm~ |
Sample Amount | Several ten grams or more |