Abstract

AEDO, Roberto E. et al. Moisture content in paper and cardboard bales through the reception power in the microwave r. Rev. cienc. tecnol. [online]. 2020, n.34, pp.1-10. ISSN 1851-7587.

The purpose of this paper is to measure the moisture content in bales of paper and cardboard through a microwave technique in the free space defined by the path of the electromagnetic wave, which in this particular work  consists on the transmitting antenna, air, sample, air and receiving antenna. Measurements were made at a laboratory scale using different test tubes that simulated bales’ characteristics with various moisture content. The interaction between the material and the microwaves is quantified by measuring the reception power within a frequency range of 3,84-12,5 GHz, and then establishing the optimal measurement frequency. In order to identify one or more calibration curves for estimating the moisture content in each bale, analysis focused on the mean distribution of the variables of interest. Results show a relationship between the reception power at different humidity contents, and that the measurements are sensible to the variability of the samples and the laboratory environment.

Keywords : moisture content; microwaves; free space; paper and cardboard bale; reception power.