CALIBRAÇÃO DO SENSOR DE CAPACITÂNCIA DIVINER 2000 UTILIZANDO TUBOS DE ACESSO PADRÃO E ALTERNATIVO - DOI: 10.7127/rbai.v11n500745

FDR devices use access tubes that have no similar products available on the Brazilian market, resulting in the need for their importation with high cost and time of acquisition. Therefore, this study aimed to calibrate a capacitance sensor for a Cohesive Yellow Argisol conditions with the use of the standard access tube of the Diviner 2000 ® and with a rigid PVC conduit, as an alternative to the standard tube. Three trenches were opened in the soil, corresponding to a state of soil moisture, i.e., dry, intermediate and moist. For each soil moisture condition, four access tubes were installed, being two tubes acquired from the Diviner 2000 ® manufacturer and two others, of the conduit type, commercially available. The moisture content measured with the conduit tube showed square root values of mean square error (RMSE) higher than those obtained with the original tube from the device manufacturer. Without local calibration, the two types of tube tested resulted in overestimation of moisture. However, the results evidenced the feasibility of using the evaluated conduit tube instead of the standard one, since the field calibration is performed.