An　inverse　problem　is　solved,　in　order　to　identify　a　current　distribution　from　measurements　of　its　magnetic　field　in　a　closed,　opaque　and　optically　difficult　to　access,　high　voltage,　vacuum　circuit　breaker.　We　have　followed　the　standard　method　of　least　squares　approximation　by　regularized　singular　value　decomposition.　We　have　verified　the　possibility　of　de-noising　the　sampled　signals　by　means　of　a　Savitsky-Golay　filter　in　the　time　domain.　Finally,　we　have　considered　the　possibility　to　increase　the　spatial　resolution　of　the　current　density　approximation　by　introducing　additional　sensors,　more　distant　from　the　circuit　breaker,　provided　that　suitable　accuracy　and　range　requirements　are　met.　©　2011　IEEE.