PCB FLUXGATE GRADIOMETER MEASURING dB_x/dy

Michal Janošek – Pavel Ripka

   In this paper, we investigated a dB_x/dy gradiometer formed by PCB fluxgate sensors stacked together with a gradiometric base of 20 and 10-mm, respectively. We discuss several possible arrangements of the gradiometer with the emphasis to a common compensating coil wound around the two sensors, which can be in a novel configuration also used for as a gradient pick-up coil. The 1-Hz noise power spectral density of the 20-mm-base gradiometer was found as 3.7 nT/m/√Hz and it increased to 8.2 nT/m/√Hz when reducing the gradiometer base to 10 mm.

Keywords: fluxgate sensor, printed circuit board, pulse excitation, gated integrators, signal extraction, magnetometer

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