THE RESEARCH AND ANALYSIS OF THE UNIFORMITY OF THE MAGETIC FIELD OF THE SQUARE HELMHOLTZ COIL

A three-dimensional magnetic field generator has been constructed taking advantage of three groups of square Helmholtz coils in order to do research on the magnetic susceptibility of optical sensors. Whether the uniformity in the center of the magnetic field is standard has to be analyzed to ensure the accuracy of test data from the optical sensor. Regarding square Helmholtz coil as four current-carrying conductor, three-dimensional space magnetic intensity and its uniformity of square Helmholtz coil were analyzed, and the result of simulating data were given. Due to that two coils may partly produce magnetic-field component possibly cancelling each other out, B-x, B-y, which can have an effect on the uniformity of the magnetic field, so that we need to evaluate the effects. First, we build a mathematical model of the magnetic field intensity of the square Helmholtz coil in the three-dimensional space. Then, some related analysis data and structural models of the three-dimensional uniform magnetic field of the square Helmholtz coil are given by Using the computer software MATLAB and LABVIEW. Finally, that square Helmholtz coils can be applied to study the magnetic susceptibility of optical sensors is proven to be feasible with the standardized testing environments of the magnetic susceptibility and evaluation methods proposed.