The precalculation step was carried out with a combination of different monodisperse Poly Styrene Latex traceable standard particles (Duke Scientific Inc., U.S.) and standard equipment of LAS-X aerosol particle counter (PMS Inc., U.S.).The statistical comparison is then made against mean values of the particle count at each channel. This calibration is repeated automatically by a computer software that adjusts the data with the accuracy of ±2%.