Aerosol mass spectrometer and method of classifying aerosol particles according to specific mass

摘要

An aerosol mass spectrometer and method for classifying aerosol particles according to specific mass wherein an outer cylinder (1) and an inner cylinder (14) are concentrically and radially spaced relative to each other to provide an annular operating space (24) between the cylinders for the passage therethrough of the sample aerosol. Outer cylinder 1 is mounted on rotor 2 to be rotatably driven thereby and has a bearing (6) at the upper end for supporting an aerosol inlet tube (8). The inner cylinder has upper and lower bearings (20, 22) in the upper and lower ends thereof for supporting an aerosol outlet tube (38). A voltage source (28) is connected between the inner and outer cylinders via brushes (30, 32) to produce a radially inward electrostatic force across the annular gap (24) to oppose centrifugal force on the particles during rotation of the cylinders. The sample aerosol flows into the apparatus through the inlet tube and passes downwardly through the operating space between the cylinders and outwardly through an outlet tube (10). At least one insulating partition (26) is provided in the operating space to establish linear or laminar aerosol flow in the axial direction. The combination of the electrostatic and centrifugal forces makes it possible to classify particles according to specific mass and thereby according to particle mass.