A Novel Chrono-Potentiometry (CP) Method for Determining the Moisture Content of Wood Above the Fibre Saturation Point (FSP)

The use of a novel chrono-potentiometry method (abbreviated as “CP”) in the determination of the moisture content in wood (abbreviated as “MC”) above the FSP is a practical application of the electrical charging effect (or ECE). In the specific case of this CP method, the ECE consists of an electrical charging phase for the wood and a discharge phase following the interruption of the charging current. The electrical resistance, R, and the electrical chargeability, Cha(E), of three hardwood species were determined from the final potential, E1, of the charging phase and the initial potential, E2, of the discharge phase, with the three hardwood species being birch (Betula spp.), aspen (Populus spp.), and black alder (Alnus glutinosa (L.) Gaertn). An auxiliary variable in the form of U (E1; E2) was defined as a function of E1 and E2. This was used as an independent electrical variable in the calibration model for a CP moisture meter for the three tree species when it came to the moisture content (MC) region above the FSP (fibre saturation point). It was found that upon a determination of the MC in the wood, the traditional calibration model (the R-model), which uses the electrical resistance of wood, was able to predict a single-measurement precision level of +/−10% for the MC while the U-model predicted a precision level of +/−1.75% for the MC over a single MC measurement in the wood.