Low-cost Impedance Measurement System for Determination of Condition and Oil Content in Wood Material

Abstract

This research aims to develop a system capable of examining the impedance response in wood materials to determine the quality of wood based on water, oil and defect conditions. The impedance measurement device is built upon the AD5933 impedance converter extended with a microcontroller and interfacing. Measurements have been performed with 100 sweeping points at an operating frequency range between 10 kHz to 100 kHz. The results are analyzed in the terms of impedance responses and phase responses. From initial testing using standard resistors, it is assessed that the measurement results are within the tolerance range (5%). The trend of the impedance (magnitude) response ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Z$</tex> ) in wood materials shows that dry wood has the highest overall against moist wood. As for the oil content in wood, it is exposed that the impedance response of cedarwood oil is larger than agarwood oil followed by cinnamon oil. Finally, the presence of a defect in wood causes its impedance response to be increased compared to those of solid wood. On the other hand, for all observed cases, the trend in the phase response (θ) is inversely proportional to the representation of its magnitude response. The paper offers a low-cost device and convenient setup for a non-destructive evaluation of the wood condition and its oil/water content.