Encontro de Energia no Meio Rural Agrener
OLIVEIRA FILHO, D., MANTOVANI, E. C. and PEREIRA, S. Tecnologia de determinação da umidade do solo via reflectometria no domínio do tempo. In Proceedings of the 3. Encontro de Energia no Meio Rural, 2000, Campinas (SP, Brazil) [online]. 2003 [cited 13 December 2013]. Available from: <http://www.proceedings.scielo.br/scielo.php?script=sci_arttext&pid=MSC0000000022000000200052&lng=en&nrm=iso> .
This paper aimed to develop an equipment for the soil moisture content measurement, based on the Time Domain Reflectometry - TDR, technique by the determination of the correlation between the soil matrix dielectric constant and its moisture content. The soil dielectric constant determination was made by the measurement of the time of a pulse to reflect in metallic probe immersed in the soil. This probe was developed in the Instrumentation Laboratory of the Energy Area of Agriculture Engineering Department of Federal University of Viçosa. The pulse electrical characteristics were determined with a 500 MHz oscilloscope. The dielectric constant, e measurements were made for a soil moisture content, U, range from 0,03 to 0,48 in dry basis (weight / weight). By a polynomial regression it was determined the following equation: that relates the moisture content and the dielectric constant of the soil.
Keywords : Soil umidity; dielectric constant; reflectometry; TDR.