Particle charge measurement: DEMC system

Particle classifier for ultrafine aerosols (4 nm to 1.2 µm) based on their electrical mobility

The DEMC series enables the user to generate monodisperse particle fractions from polydisperse ultrafine aerosols with up to 64 size classes per decade.

The DEMC (see also ISO 15900) selects the particles based on their electrical mobility. If the DEMC is used as a component of an SMPS system, then the voltage and thus the electrical field change continuously and particles of varying mobility consecutively exit the DEMC. Particle counters, such as the UF-CPC or the Charme® count the particles of the individual monodisperse fractions.

Reliable software combines the data (voltage, particle number, etc.) in order to obtain a particle size distribution. The DEMC software and firmware support the use of nanoparticle counters by other manufacturers.