Characterization of particles using an electric cascade impactor

The particle size distribution is recorded during laser material processing using an Electrical Low-Pressure Cascade Impactor (ELPI). Afterwards, the percentages of the different particle fractions are calculated taking into account the sampling volume (partial volume flow extraction). The total mass flow is determined gravimetrically. For this purpose, the workpieces are weighed before and after the laser processing. In the case of a laser cutting process, the total emission (gaseous and particulate components) is derived additionally from the cutting kerf geometry and the cutting speed for comparison.