Resolution

For the resolution of a laser diffraction particle size analyzer (i.e. particle size analyzer that operates based on the laser diffraction/scattering method), division of a range about 0.1 to 1000 µm into 50 to 70 sections on a logarithmic scale is considered to be the substantial resolution limit. However, attention must be paid not to confuse resolution with number of divisions since the number of divisions in calculation can be increased by any amount.

Also, it is difficult to quantitatively express resolution in µm units since resolution is considered to be referenced to logarithmic scale as shown above.

A feature of a laser diffraction particle size analyzer is represented by its capability to measure over a wide measurement range in a single operation. This, however, does not mean that it has high resolution way above other principles of measurement. Also, due to the principle of measurement of these analyzers, even supposing that a measurement target (sample) comprising only particles of uniform size and having no substantial particle size distribution range is measured, measurement results having a fixed distribution range will be obtained. In other words, a laser diffraction particle size analyzer does not measure the particle size of each individual particle; it measures the particle size distribution of a particle group made up of numerous particles. Thus, it is fairly difficult to accurately differentiate between 5.00 µm and 5.01 µm size particles.