Particle charge-size distribution measurement using a differential mobility analyzer and an electrical low pressure impactor

ABSTRACTWe introduce a particle charge-size distribution measurement method using a differential mobility analyzer and an electrical low pressure impactor in tandem configuration. The main advantage of this type of measurement is that it is suitable for a wide range of particle sizes, from approximately 30 nm up to a micrometer, and for high charge levels, which have been problematic for previously used methods. The developed charge measurement method requires information on the particle effective density, and the accuracy of the measurement is dependent on how well the particle effective density is known or estimated. We introduce the measurement and calculation procedures and test these in laboratory conditions. The developed method has been tested using narrow and wide particle size distributions of a known density and well-defined particle charging states. The particles have been produced by the Singly Charged Aerosol Reference (SCAR) and an atomizer and charged with the previously well-characterized ...