“…For particles lower than 1 μm, diffusion charging is the dominant charging mechanism. The number of charges for field charging, n f t ð Þ, and that for diffusion charging, n d t ð Þ; can be estimated from the following equations (Lin, Chen, & Tsai, 2012;Chen, Tsai, Yan, & Li, 2014;Najafabadi, Tabrizi, Aramesh, & Ehteram, 2014).…”