A Simple Iteration Procedure to Correct for the Density Effect in the Aerodynamic Particle Sizer

Abstract

A simple iteration procedure is developed to correct for the density effect in the Aerodynamic Particle Sizer. The correction is appreciable for large particles due to ultra-Stokesian drag. For submicron particles, the correction is less than 4% and is caused by the change of the slip correction factor across the accelerating nozzle. Both corrections were included in the procedure to calculate a new calibration curve at a desired particle density from a standard calibration curve. The iterations converge very fast; a microcomputer program has been developed which can calculate a 20-point calibration curve in less than 5 seconds. The results of the present procedure are in excellent agreement with the supercomputer calculations of Ananth and Wilson (1987).