Atmospheric Measurement Techniques
We have designed and characterized a new inlet and aerodynamic lens for the Aerodyne aerosol mass spectrometer (AMS) that transmits particles between 80 nm and more than 3 µm in vacuum aerodynamic diameter. The de-sign of the inlet and lens was optimized with computational ﬂuid dynamics (CFD) modeling of particle trajectories. Ma-jor changes include a redesigned critical oriﬁce holder and valve assembly, addition of a relaxation chamber behind the critical oriﬁce, and a higher lens operating pressure. The transmission efﬁciency of the new inlet and lens was char-acterized experimentally with size-selected particles. Exper-imental measurements are in good agreement with the calcu-lated transmission efﬁciency
Williams, L. R.; Gonzalez, L. A.; Peck, J.; Trimborn, D.; McInnis, J.; Farrar, M. R.; Moore, K. D.; Jayne, J. T.; Robinson, W. A.; Lewis, D. K.; Onasch, T. B.; Canagaratna, M. R.; Trimborn, A.; Timko, M. T.; Magoon, G.; Deng, R.; Tang, D.; Blanco, E. de la Rosa; Prévôt, A. S. H.; Smith, K. A.; and Worsnop, D. R., "Characterization of an Aerodynamic Lens for Transmitting Particles Greater than 1 Micrometer in Diameter into the Aerodyne Aerosol Mass Spectrometer" (2013). Space Dynamics Lab Publications. Paper 164.