Two butanol-based Condensation Particle Counters (CPC 3022, CPC 3025), three water-based CPCs (CPC3781,CPC3785×2), a Gardner Counter, a Fast Mobility Particle Sizer (FMPS), and an Aerosol Electrometer (AE) weredeployed to measure the number concentrations from atomized aerosol under six different conditions. Comparisonsof particle number concentrations measured by the CPCs, FMPS, and AE were conducted to evaluate the performanceof the each CPCs using laboratory generated artificial particles such as NaCl, succinic acid (C4H6O4), andparticles generated by propane torch & heat gun in the chamber. Good correlation between the CPC3025 and FMPSwas observed for the total particle number concentrations in the size range 15 nm to 90 nm. In addition, this papersuggests that photometric mode in water-based CPC3785 could not be used as quantitative of number concentrationsfor CPC3785.