A Method of Measuring the Ion Spectrum

Abstract

In measuring the mobility-spectrum of the ions in the atmosphere, by means of the cylindrical condenser of the type of Gerdien's aspiration apparatus, we must calculate the second differential coefficient of the voltage-current characteristic curve. But it is very difficult to derive this from an experimental curve. Furthermore, the variation of ion contents during the observation can not be neglected without causing appreciable error to the result.
I used Nolan's “Sub-divided Condenser”, and devised a method in which we have only to derive the first differential coefficient for this purpose.