Particle size (particle diameter)

The size of the same particle can change depending on the perspective.

The particle diameter of a true sphere is uniquely determined. However, non-spherical particles can vary in size depending on the measurement method. For example, ground materials have different shapes for each individual particle. Therefore, to determine the overall size of a powder from individual particle diameter measurements, it is necessary to measure a large number of particles using the same method and statistically determine the particle size. In visual inspection or image analysis, it is common to measure the "equivalent diameter," which is the size of a particle with an ideal shape (usually circular) equal to the projected area of the particle, or the "directional diameter," which measures the length in a specific axial direction for randomly oriented particles. Additionally, there is the aspect ratio, which represents the ratio of the long axis to the short axis of the particle. Our particle size distribution measurement device measures particles as aggregates, so it cannot be discussed on the same level as measurements taken with microscopes and similar instruments. Among the Microtrack methods, the laser diffraction method outputs the particle size distribution of an aggregate of spherical particles that exhibit a scattering pattern equivalent to the obtained light scattering pattern. The dynamic light scattering method outputs the sphere-equivalent diameter based on diffusion. *For more details, please refer to the related links or feel free to contact us.*

Other measuring instruments