Medidor de intensidad de campo magnético para lazos de inducción
The need to measure the magnetic field strength distribution over the area covered by an induction loop fitted as hearing aid for people with hypoacusia was the main reason that led the rehabilitation task group to address the design and implementation of an instrument with the following features: easy calibration and adjustment to IEC 60118/4: 2006 standards. Based on the experience gained in the construction of induction loops and the consequent design of the amplifier and the impedance matching transformers, the task group carried out the design of an instrument based on a field sensor which is still under evaluation. In order to develop a deeper understanding of the system’s theoretical behavior, mathematical expressions were previously developed so as to quantify the magnitudes of the field strength space components in Cartesian coordinates through Matlab® software. Once the instrument has been calibrated through magnetic sources of known geometry and intensity, the task group proceeded to validate the developed mathematical model. After comparing analytical results against published tests of commercial instruments, the group was able to conclude that both space distribution patterns matched each other.