Measurement of atmospheric radon daughter concentrations at the campus of Fukushima Medical College.

Radon daughter concentrations in outdoor and indoor air were measured at the campus of Fukushima Medical College. Radon daughters in the air were sampled with a flow rate of 20 L/min through a glass fiber filter or a membrane filter, and the decay of activity on the filter was analyzed with two types of technique, i.e., the gross-beta one-count method using a G.M. tube and the alpha spectroscopic method using a semiconductor detector. The present paper describes principles and techniques of the measurement in detail.