CW metal detector based on AMR sensor array

We developed an eddy-current metal detectors with Anisotropic Magnetoresistors (AMR´s) arranged in a 4×4 array. The magnetoresistive sensors in a gradiometric configuration are sensing the vertical component of the magnetic field - either originating from magnetized ferromagnetic bodies or induced by 1-kHz, alternating continuous-wave excitation. The AMR´s are arranged so that the homogeneous Earth´s field and the large excitation field can be suppressed. The mine-detector was constructed as a standard portable device. The presented results show that the performance is limited by the noise of the selected magnetoresistive sensor. If the size of the sensor array was increased, the system could form an advanced mine-detector for quick, large-scale demining purposes.