Improvement of simple impedance tomography method in RF range for estimating moisture distribution in squared timbers

Abstract

Improvement of the simple tomography method for estimating moisture distribution in squared timbers was conducted by using impedance measurement in the RF range at 250 kHz. The local impedance in the horizontal and vertical directions was measured during natural drying. An inverse procedure using a trial-and-error method was used to reconstitute the cross-sectional moisture distribution from the surface impedance measurement. Two essential corrections for the spatial heterogeneity of the electric field between electrodes and for the calculation error due to the algorithm of the trial-and-error method were introduced to improve the accuracy of the reconstitution of the moisture distribution. The reconstituted moisture distribution matched well that determined by the oven-dry method. © 2010 The Japan Wood Research Society.