This paper presents a theoretical analysis of the effect of space-charge on the performance of differential mobility analyzers. The mathematical treatment, which is carried out for non-diffusing monodisperse aerosol particles, is based on the calculation of the electric field (applied plus space-charge) along particle trajectories, and leads to a simple expression for the classification voltage as a function of two dimensionless parameters. The effect of aerosol properties (mobility, concentration), DMA geometry and operating conditions on the classification performance is discussed. The model predicts that space-charge affects the DMA performance for values of noZ, larger than about 22,000 V-I cm -1 (no is the particle number concentration at DMA inlet; Z the electric mobility; , the mean aerosol residence time).
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机译：本文对空间电荷对差分迁移率分析仪性能的影响进行了理论分析。对不扩散的单分散气溶胶颗粒进行的数学处理是基于沿颗粒轨迹的电场（施加的加空间电荷）进行的，并且得出了分类电压随压力变化的简单表达式。两个无量纲参数。讨论了气溶胶特性（迁移率，浓度），DMA几何形状和操作条件对分类性能的影响。该模型预测，当noZ值大于约22,000 V-1 cm -1时，空间电荷会影响DMA性能（no是DMA入口处的颗粒数浓度; Z是电迁移率;平均气溶胶停留时间）。
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