Differential mobility analyzer for nano particle sizing

The performance of four DMAs, namely, the TSI-long, the TSI-short, the Hauke 3/150, and the SMEC are evaluated under the same conditions of flow rates, flow ratio, input monodisperse aerosols and transport-line lengths. The transfer functions of all four DMAs are obtained by deconvoluting the scan results of the evaluated DMA (DMA2), and by using the empirical transfer function of the first DMA (DMA1) which was used to generate the test monodisperse aerosols. The half-width, height, and area of the transfer functions have been compared in the size range of 6 nm to 50 nm. These results provide a quantitative comparison of the mobility resolution and diffusion loss of the nanometer aerosols in the DMAs. The evaluations are performed under the conditions of 10 l/min sheath air and 1 l/min aerosol flow rates and at a flow ratio of 10:1.