Correlation Between Prototype Advanced Halfmini DMA and Commercial SMPS Measurement of Combustion-generated Solid Sub-23 nm Particles

The Advanced Halfmini DMA was initially developed by De la Mora & Kozlowski (2013) for high resolution measurement, at ambient temperature. After recent modifications the system enables exhaust aerosol measurements with an extended particle size range (30 nm), at high temperatures (200°C). In this modified system, particle charging occurs by a Secondary Electrospray Ionisation charger which is adopted for hot aerosols. However, determining the charging efficiency of such a unipolar charger is a challenging task. In this study, we performed a preliminary experimental correlation of the prototype Advanced Halfmini DMA ions concentration signal to SMPS particle concentration, generated either by a standard propane burner or a diesel engine. Correlation of prototype Advanced Halfmini DMA ions concentration to SMPS particle concentration follows a size-dependent exponential relation. Such correlation was used in GDI sub-30nm particle measurement to correct prototype’s raw signal to particle number concentration with commercial DMS500. This work was supported by the Horizon 2020 E.U. Progr., through SUREAL-23 project (G.A.724136).