Influencia de la frecuencia de excitación y la distancia entre enrollados durante el sensoramiento de la conductividad eléctrica del suelo mediante un campo magnético variable.

A theoretical-experimental study of the electromagnetic field-soil interaction is made using the finite element simulation, as well as the experimentation in a soil container. As a result the influence on the soil response to the action of a variable electromagnetic field is determined in function of the excitement frequency of a field-generator coil and of the distance between the field-generator coil and a receiver coil, measured through the current induced in the last one. Validation criteria of the use of finite element analysis during the study of the interaction among a variable magnetic field with the soil are obtained. Also is obtained that the excitement frequency that causes the maximum induction in the receiver coil lies between 10000 and 15000 Hz, with a tendency to grow when coil distance is increased. It is appreciated that only in this range of frequencies it is possible to discriminate changes in soil electric conductivity by means of the electromagnetic field. It was determined, by finite element simulation, an exponential tendency to decrease the maximum density of the induced current in the receiver coil in function of coil distance, with an asymptote in the axis of the abscissas, that is interpreted like a null induction when the coil distance tends to infinite. The same tendency was obtained through the experimental way on a red feralitic compacted soil. [ABSTRACT FROM AUTHOR]