Portable particle spectometer

A system for characterizing particles in an aerosol, the system comprising:

• a collection container comprising:
• a first end having an opening;
• a second end, wherein the collection container is configured to be oriented such that an axis of symmetry extending from the first end to the second end is oriented substantially in a direction of gravitational settling of the particles;
• and
• a collection container wall extending between the first end and the second end, the collection container wall having an inner surface defining a collection chamber;
• a first flow device coupled to the second end and configured to provide a first fluid flow from the second end toward the first end, wherein the first fluid flow is configured such that particles having a first aerodynamic diameter settle into a measurement region of the collection tube;
• a particle detector operatively coupled to the collection container, wherein the particle detector is configured to detect at least one particle within the measurement region of the collection chamber;
• a housing, wherein at least a portion of the collection container is disposed within the housing, the housing comprising:
• a first housing end having a cap disposed above, and spaced apart from, the first end of the collection container, the cap having an inlet aperture defined therein;
• a second housing end;
• and
• a housing wall extending downward from the first housing end such that at least a portion of the housing wall is positioned external to, and spaced apart from, the collection container wall, thereby forming a gap between an outside surface of the collection container wall and an inside surface of the housing wall;
• and
• a second flow device operatively coupled to the housing and configured to provide a second fluid flow, within the gap, away from the first housing end, thereby creating a fluid stagnation region above the first end of the collection container.