Experimental investigations on the spatial resolution in RTD-Fluxgates

This paper discusses about the spatial resolution performance on RTD-fluxgate prototypes having different ferromagnetic core geometry. This is of major importance when the magnetic target signal source is very confined in space and therefore the ability of the sensor to correctly point the target is dictated by its ability to resolve the target position. The readout strategy is based on the use of the residence times difference (RTD), where the DC magnetic field information is derived from the temporal positions of the output waveform spikes. The experiments and studies reported here give guidelines for the optimal design in terms of spatial sensing capabilities. The ability of the sensor to locate the position of a DC B-field source is therefore characterized and related to the shape of the core adopted for the sensor fabrication. Two core types have been considered: ribbon and wire. 3 D diagrams have been developed in order to evaluate the time domain response as function of a known magnetic source position.