Ion spectra of various bipolar chargers, their capability to achieve charge equilibrium and influence on nanoparticle measurement

摘要

Many techniques for the measurement and manipulation of aerosol nanoparticles utilize electrical methods which makes the charging of nanoparticles an essential requirement for their use. Likely the most common application of a charge conditioner is the use in combination with a differential mobility analysis (DMA). For this purpose usually a bipolar diffusion charger is used. Different bipolar aerosol chargers, an AC-corona, a soft X-ray (SXR) and α-radiation based Am-241 charger were investigated regarding the ion-spectra produced by those chargers, as well as their charging performance of nanoparticles. Chargers were operated under various flow conditions: in the range 6-16 lpm for spectra measurement and in the range of 0.5 - 5.0 lpm for charging probability measurements and comparison with the theory.