Experimental characterization of the static magnetic field generated by railway filters

An experimental procedure for the characterization of the static magnetic field generated by resonant filters installed along the railway infrastructure is proposed. The inductor current and the magnetic flux density are simultaneously measured in situ, i.e., during the normal operation of the railway system. An algorithm based on linear regression is used to process measurement data in order to estimate the parameters of a linear model which correlates the magnetic field and the current. The obtained model is a fundamental tool to assess magnetic-field levels with reference to human exposure.