Articles | Volume 6, issue 11
Research article
28 Nov 2013
Research article |  | 28 Nov 2013

Characterization of an aerodynamic lens for transmitting particles greater than 1 micrometer in diameter into the Aerodyne aerosol mass spectrometer

L. R. Williams, L. A. Gonzalez, J. Peck, D. Trimborn, J. McInnis, M. R. Farrar, K. D. Moore, J. T. Jayne, W. A. Robinson, D. K. Lewis, T. B. Onasch, M. R. Canagaratna, A. Trimborn, M. T. Timko, G. Magoon, R. Deng, D. Tang, E. de la Rosa Blanco, A. S. H. Prévôt, K. A. Smith, and D. R. Worsnop

Abstract. 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 design of the inlet and lens was optimized with computational fluid dynamics (CFD) modeling of particle trajectories. Major 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 characterized experimentally with size-selected particles. Experimental measurements are in good agreement with the calculated transmission efficiency.