| 摘要 |
The invention relates to a magnetic sensor device (10) comprising two excitation wires (11, 13) for the generation of first and second magnetic fields (B<SUB>1</SUB>, B<SUB>2</SUB>) that dominate in a first and a second investigation region (5a, 5b), respectively. A Giant Magneto-Resistance (GMR) sensor (12) is disposed in the middle between the excitation wires (11, 13) and senses stray fields (B') generated by magnetized beads (2) that are bound in one (5a) of the investigation regions. As the excitation wires (11, 13) are fed with anti-parallel currents (I1, 12), the components of the first and second magnetic fields (B1, B2) in the sensitive direction (D) of the GMR sensor (12) compensate each other in said sensor (12), thus minimizing interferences from crosstalk. A similar cancellation of stray fields (B') is prevented by providing one (5b) of the investigation regions with an exclusion zone that prevents the binding of magnetized beads (2) there. |
