A device, an arrangement, and a method for measuring a current intensity in a primary conductor through which current flows are disclosed. In an embodiment, an apparatus includes a magnetic field-generating element configured to generate a reference magnetic field; and a magnetic field angle-sensitive element configured to measure an orientation of a total magnetic field, the total magnetic field is produced by overlapping of the primary magnetic field and the reference magnetic field in space, wherein the primary magnetic field and the reference magnetic field are not parallel to one another at a location of the magnetic field angle-sensitive element, and wherein the current intensity of the current flowing through the primary conductor is determinable from the orientation of the total magnetic field in space.