Desenvolvimento de sistema eletrônico para tomografia de indução magnética / Electronic system development for magnetic induction tomography

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

29/08/2011

RESUMO

Magnetic induction tomography is a contactless conductivity imaging technique. This technique uses a magnetic field generator (usually a coil) to induce Eddy currents in the target object and several magnetic sensors (usually coils as well) that capture the magnetic field generated by these induced currents. The measurements obtained by these sensors can be used to construct a conductivity image of the space inside the tomograph. The purpose of this dissertation is to develop an electronic system for magnetic induction tomography. The main objective is to detect the magnetic field generated by the induced Eddy currents measuring the disturbance on the phase of the sensors signal when a conductive object is placed inside the tomograph. Coils were used as magnetic field sensors and generator. The frequency used to generate the excitation fields and also on phase detection circuit were 10.7 MHz. The system is capable to measure only one sensor and enable only one generator at a time. A system with 16 sensors and 16 generators was achieved through multiplexing. All the electronics were analyzed and results are shown on this dissertation. Also a preliminary tomograph prototype was build and some measurements were taken and compared to measurements done by commercial electromagnetic sensor and a scope. For a 1 S/m sample the average square error on the measurements compared to simulations was 0.41.

ASSUNTO(S)

tomografia campo magnético detecção de fase automacao eletronica de processos eletricos e industriais tomography magnetic field phase detection

ACESSO AO ARTIGO

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