permeable concentrator 220 when a field is applied along the x direction note that the applied field is steered in the upward direction on the left hand side of permeable concentrator 220 and downward on the right hand side of permeable concentrator 220 z axis magnetic field sensors placed at the left and right hand sides of the permeable concentrator will thus show opposite changes in resistance to fields applied in plane the difference between the resistance values of the two sensors at opposite sides of the permeable concentrator 220 is thus indicative of the x axis field and it should be insensitive to fields applied along the z and y directions thus the configuration of sensor shown in fig5 should be useful for isolating different components of the applied magnetic field neither vector magnetometer concept illustrated in fig4 and 5 are expected to perfectly isolate the different magnetic field components and there will be cross axis sensitivity in each of the different sensors to components that are not along the intended sensitivity axis in order to resolve this problem and also to overcome any non orthogonality between the sensitivity axes a sensor system such as depicted in fig8 can be constructed the operating principle for the vector magnetometer system involves treating the voltage output from each of different sensors as a sum of three polynomials of the different field directions h x h y and h z along with a dc offset voltage the following form is suggested v 1 u2212 v 1 off c 11 x h x c 11 y h y c 11 z h.