Resumo:
Electroresistivity is a geoelectric method that consists in estimating the electrical resistivity to investigate the structural composition of the shallow subsurface. However, commercial equipment has a high acquisition and maintenance cost. The objective of this research is to develop a multichannel, 16-electrodes, modular, automated and programmable electrical resistivity (ER) measuring instrument, based on some deficient aspects of the commercial equipment. To this end, a conceptual prototype of a microcontrolled resistivity meter was built, with a graphic interface, based on free software and hardware technologies, as a low cost alternative for the acquisition of physical parameters with the same accuracy as commercial equipment. The results demonstrated the feasibility of the conceptual project, design and representation as an important academic contribution to open source instrumental research. The implementation of the electrode multiplexing technology, made the process more efficient with the switching and reduced amount of relays distributed along the cable, in the same way that synchronous demodulation provided an elimination of spurious noise, noise not correlated with the excitation source.
