Room temperature three sensor magnetic field gradiometer

We have constructed a portable magnetic field gradiometer from fluxgate magnetometers using a novel common‐mode rejection method. The sensor, known as a room temperature Three Sensor Gradiometer (rtTSG), is, as far as we know, the first hand‐held gradiometer that can measure all components of the magnetic field gradient tensor. The rtTSG can measure these components in motion at a noise level of about 1.4×10−10 T/m√Hz at 1 Hz. Real time tracking of magnetic dipoles while the gradiometer is in motion has been demonstrated.