A Preliminary Study by a Slow Expansion Chamber

Abstract

The air in an expansion chamber was expanded in fairly slow speed through different each filter to change the cooling rate of air. Size distributions and concentrations of activated droplets thus obtained were examined and the selection effect was found out on the concentrations according to the cooling rate and initial dew point.
An empirical formula was presented on the concentrations of droplets and the constant in the size distribution after Best was decided from these results.
The mixed distribution of condensation nuclei (soluble and insoluble) in the test air are presumed to illustrate the produced flat size distributions.