Abstract: A method of determining the moisture content of charge of wood having a moisture content below fiber saturation and being subjected to a Radio Frequency dielectric heating process to the degree required to control the process (e.g., terminate drying) by measuring the wood product package dimensions and monitoring the RF power KW and RF voltage KV being applied to the charge at the electrode(s) and further controlling (i.e., terminating) the process when the KW and KV being applied based on a pre-selected function indicates that the charge has reached a preselected moisture content.