On The Measuring Electrodes for Moisture Content in Powdery and Granular Materials

Special Concentric Cylinder Electrodes

Abstract

The dielectric method for accurate and rapid measurement of moisture content in powdery and granular materials has been developed as a substitute for a resistance method. By this method is measured the capacitance variation which has a direct relation to specimens inserted in a measuring electrode. In that case, the special concentric cylinder electrode is used, instead of the concentric circle type grid electrode in the previous paper.
This paper deals with the construction of the special concentric cylinder electrode and describes experimental results of both the effect of sampling weight, and the interrelation among length of electrode, dielectric constant and capacitance variation in electrodes with various geometrical constructions.
The performances of various electrodes, in which are inserted glassbeads, granulated sugar, wheat and tablets, are investigated by comparing the dispersions of measured values of capacitance.
Finally, moisture content in granulated sugar and wheat, measured by this method, are described.