The Effect of Sensor Size on Axial Gradiometer Performance

Abstract

The case of a finite base gradiometer with ideal sensors is considered, then influence of finite-size sensing elements is modeled and finally, comparison with experimental results obtained with two ring-core fluxgates and two AMR sensors are evaluated. Some of the effects found may be counterintuitive and especially in the close proximity of dipole source, the gradient cannot be further modeled by simplified uniaxial approximation because of the sensor size. Full Biot-Savart field model was considered in those cases.