Abstract: The invention relates to a magnetic sensor device (10) comprising magnetic field generators (11, 13) for generating a magnetic excitation field (B) in an investigation region and a magnetic sensor element (12) for measuring magnetic reactions fields (B?) generated by magnetized particles (2) that are bound to binding sites (3) in the investigation region. Both the magnetic field generators (11, 13) and the magnetic sensor element (12) are driven with electrical power, wherein the ratio of the power that is dissipated in said components is kept in a predetermined interval. The magnetic field generators may preferably be realized by excitation wires (11, 13) and the sensor element (12) by a magneto-resistive element, for example a GMR element. In this case, it is preferred that about equal amounts of power are dissipated in the excitation wires (11, 13) and the GMR element (12).

Abstract: Consistent with an example embodiment, devices comprise sensor arrangements with field detectors for detecting components of magnetic fields in planes of the field detectors. The sensor arrangements further include movable objects for, in response to tilting movements, changing at least parts of the components of the magnetic fields in the planes of the field detectors so that the sensor arrangements are made less sensitive to in-plane stray fields by providing the field detectors with saturated field-dependent elements. The movable object may comprise a movable field generator for generating the magnetic field, or the movable object and the field generator may be different objects. The magnetic field is such that the field-dependent element is saturated. The field generator is smaller than the field detector, and the movable object is larger than the field detector, to reduce alignment problems. The movable object has a pivoting point close to the field detector.