Some experiments have been therefore performed it) test the possibility of performing resistivity tomography. The equipment used for both laboratory and field measurements, is a multi-electrodes georesistimeter for geophysical surveying STING (AGI, Ltd) modified to be used with. electrodes suitable for measturements on trees. Investigations wore performed with 16 equidistant electrodes for each section and data were processed by 'quasi Newton algorithm" implemented in Matlab. Fieldwork consisted on data acquisition on. living trees showing signs of internal decay, In some cases, trees were cut down after data acquisition and lab measurements were carried out on wood disks arid samples. The method showed. its reliability and its good resolution in detecting the geometry of wood decays but it shows some limitations: there is a strong variability in electrodes contact resistance, that affects the result reliability, and the electrode positions have to be measured with adequate precision. We can get over the first limitation by measuring electrical permittivity - Electrical Capacitance Tomogyraphy - instead of resistivity but the sensitivity of this parameter has to be assessed because of its narrow dynamic range, To solve the second limitation, it is necessary to measure parameters that have no length dimension, like the loss factor In spite of the increasing of the complexity. hardware and software, this integrate approach is now in progress.

Interpretation of tomographic images can also be improved by setting up equalization models based on typical physical behaviour of wood, For this purpose. systematic analyses of the electrical properties of wood in progressive decay conditions are going to be performed.