An Approach to Calibrate EMI Multifrequency Sensor

Nowadays electromagnetic induction (EMI) methods are common approach to solving a wide range of ecological, geotechnical, archaeological and agricultural shallow depth problems. For the determination of apparent and true values of ground resistivity the device calibration should be performed. Usually calibration is a single experiment above a known conductive half-space or its simulation by metal coil. But such a way is insufficient for a multifrequency sensor calibration which action can not be explained in the terms of low frequency approximation. The paper explains the new calibration approach. It uses a minimization procedure for oversaturated system of experimental data to make possible finding and correcting quite a large amount of device parameters. Its values are needed to be precisely known for the quantitative data processing. The practical application for the existing portable multifrequency sensor NEMFIS is shown as well.