"TSI 3936 Scanning Mobility Particle Sizer"@en . . "SDN:L22::TOOL0423" . "A differential mobility analyser that measures the size distribution and concentration of aerosol particles. It includes a cylindrical detection chamber with a variable-voltage collection rod running centrally along its length. The aerosol sample is introduced to the axial laminar flow of the chamber, where particles are deflected toward the collection rod by its electric field. Only particles within a narrow range of sizes, and thus a narrow range of mobilities, have the necessary trajectory to exit to the particle counter. The instrument is programmed to scan through a range of voltages, thereby varying the size of particles to be counted. The SMPS can scan through its full diameter range, 0.0025 um - 1 um, in 16 seconds. The scanning period can be increased to improve resolution at low concentrations. At its highest resolution, the SMPS can distinguish particle counts in 167 size bins."@en . .