Until now, the edge effect in finite-size, low field magnetoelectric sensors was routinely neglected, that is it was assumed that uniform external magnetic field produces a uniform internal magnetic field in the sensors. In this study, the internal magnetic field in a three-layer Terfenol-D/PZT/Terfenol-D laminate magnetoelectric sensor was computed using finite-element method based software COMSOL. It is shown that the internal magnetic field is not by far uniform, in particular inside the magnetostrictive material. An indirect influence of the internal magnetic fields non-uniformity was measured. A special adjustment of the non-uniform permanent magnets driven bias of the sensor proved capable of marked reducing the internal magnetic fields non-uniformity, and in this way enhancing the responsivity of the sensors studied.