Abstract
To examine the effect of probe diameter on isokinetic sampling errors, experimental studies were conducted using methylene blue-uranine aerosol generated by a spinning disk and lycopodium spores in the small and large inertia regions, respectively. From the results, it is found that the standard deviation of concentration ratio, defined as the ratio of concentration measured by a probe of any diameter to that by a one-cm diameter probe, is larger as the probe diameter decreases. It is also found in the small inertia region that the mean values of concentration ratio measured by smaller diameter probes are different from one another and deviate significantly from unity in some cases.
