Atmospheric Measurement Techniques (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,
  • D. R. Worsnop

DOI
https://doi.org/10.5194/amt-6-3271-2013
Journal volume & issue
Vol. 6, no. 11
pp. 3271 – 3280

Abstract

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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.