As major findings of this research, significant differences in MMDs and GSDs of filter-based samples collected in the layer house were detected when comparing PSDs measured with three different particle size analyzers. Different principles and characteristics of these analyzers led to the differences in PSD measurements. In general, the LA-300 (laser scattering particle size analyzer) provided the largest MMDs, whereas CCM3 (Coulter Counter Multisizer3) gave the smallest ones. LS13 320 analyzer (multi-wavelength laser diffraction) provided the largest GSDs, whereas CCM3 analyzer gave the smallest. The PSD results of testing aerosols measured by different instruments were generally consistent with that of filter-based samples. In general, LA-300 provided larger MMDs, whereas LS13 320 and LS230 (laser diffraction particle size analyzer) provided larger GSDs than LA-300 and CCM3. It was observed that the PSD results from two LS series analyzers (LS 13 320 and LS230) agreed well with each other.