Determining moisture content in a broad range of sawdust from microwave transmission measurement using microstrip line

Using microstrip line for determining moisture content in a broad range for samples of sawdust is described in this paper. The determination was based on the measurements of the attenuation and phase shift of an electromagnetic wave transmitted through a layer of wet material that is placed onto the microstrip line. The measurements were made at two frequencies (6GHz and 9GHz) on sawdust samples of varying dry densities (0.13-0.20g/cm(3)) at room temperature. The changes of attenuation and phase shift at the two frequencies were used to obtain the density-independent calibration equation Experimental results for sawdust in moisture range of 10 to 190% on dry basis are presented. The average error in moisture content determination was 4.65%.