Hosokawa Mikropul E-Spart Analyzer

Electrical Single Particle Aerodynamic Relaxation Time (E-SPART) Analyzer simultaneously measures size in the range from submicron to 100 pm and particle charge distribution from zero to saturation levels [177,178]. 

The operating principle depends upon the phenomenon that when an airborne particle is subjected to an oscillatory external force, such as 

In a further paper, the instrument was applied to the size and charge analyses of toners [180]. The size range for toner was limited to 2 pm to 25pm a lower acoustic frequency is used in the improved E-Spart that increases the upper size limit, for glass beads, to 50 pm [181]. 

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