Modification of the ELPI to measure mean particle effective density in real-time

A new modification of electrical low pressure impactor (ELPI) for the particle effective density measurement is presented. The system is capable of real-time operation and it is based on the serial measurement of mobility and aerodynamic diameter. In the studied configuration, a zeroth order mobility analyser is installed inside of the ELPI-instrument. The system is feasible for single modal distributions. For several particle materials and varying size distributions, the measured average density values were within 15% of the values obtained with a reference method.