抄録
The 6 stage Andersen samplers for microbiological particles, which have been utilized as the standard apparatus for the measurement of size distribution, are not able to determine the upper limit of the 1 st stage only as larger than 8.0μm. The larger particles have grave influences on the data especially when the contamiantion takes the form of the settlements of particles. First we made experiments with traditional 6 stage Andersen samplers using three kind of sampling rates to extend the upper limit of the 1st stage to find it was not enough. Next we attached two new stages ( -1st and 0th stages) on top of the 1st stage of the traditional 6 stage sampler which allowed us determine ranges of 15-23μm, 23-45μm respectively. Actual measurements showed that the correlation of settled microbes and Andersen sampler samples collected on the -l〜lst stages were far better than settled and those collected on the 2〜6th stages.
