Moisture Content Measurement in Scots Pine by Microwave and X-Rays


  • Tommy Vikberg
  • Johan Oja
  • Lena Antti


Wood, inline, attenuation, phase shift, knots


There is demand in the Swedish sawmill industry to improve the accuracy of moisture content measurements, both to obtain a better tool to run production and to ensure that the products meet customer expectations. In this study, 240 well-conditioned pieces of Scots pine (Pinus sylvestris), sorted into five different groups by visual inspection, were measured using microwaves and X-rays. Models to predict moisture content of wood were made by measurements of an additional 45 pieces of wood. Using only measured quantities from the microwave system, ie attenuation and phase shift, the root mean square error (RMSE) of the estimated moisture content was 1.00%. By adding total density from the X-ray measurements, RMSE of the estimated moisture content was lowered to 0.89%. Mean errors of the different wood groups varied from -0.65 to 0.18%.


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Research Contributions