"1" . . "2011-09-06 17:41:15.0" . "false" . . "TSI 3321 Aerodynamic Particle Sizer"@en . . "SDN:L22::TOOL0422" . "The TSI 3321 Aerodynamic Particle Sizer (APS) measures the size distribution and concentration of aerosol particles in the diameter range 0.5 - 20 um. The aerosol sample is accelerated toward the detection area, where it crosses two slightly overlapping laser beams. The rate of acceleration is determined by the particle size. Larger particles accelerate more slowly due to their greater inertia. Light scattered by each particle is focussed onto a photodiode. The use of twin lasers results in a two-crested signal. The peak-to-peak time-of-flight is used to determine the particle velocity, and thus its aerodynamic size. The amplitude of the signal may be used to provide an alternative measure of particle size through light-scattering techniques."@en . "SDN:L22::TOOL0422" . . "1" . . "2011-09-06 17:41:15.0" . "SDN:L22::TOOL0422" . "accepted"@en . . . "TSI 3321 APS" . "TSI 3321 APS"@en .