Low-frequency magnetic-field immunity surface scan method

Many sensor designs incorporating electronics are becoming more vulnerable to low frequency (LF) magnetic field (H-fields) when used in close proximity of electrically driven actuators, linear and rotating motors. The complex geometrical structure of the sensor´s front-end design is often unknown. The sensor´s front-end position is where the physical measurement quantity is transferred into an electrical quantity and then led up to the amplification stages. Again, given by the fact that low-frequency H-fields are hard to shield, the externally generated H-fields i.e. magnetic flux penetrates into the few sub-mm square area and induces interfering voltages: U = −dφ/dt = −dB.A/dt.