Simulation of magnetic field distribution of excitation coil for EM flow meter and its validation using magnetic camera

Distribution of magnetic flux density in electromagnetic (EM) flow meter is significantly important for obtaining accurate flow rate. Analysis of Helmholtz coils used to generate homogeneous magnetic flux density in the cross section of flow pipe of electromagnetic (EM) flow meter is presented in this paper. In this work a simulation model with the EM module of finite element analysis software, COMSOL, is built and experimental testing of the distribution of magnetic flux density is applied to verify its uniformity. A 2D magnetic camera system with 64 Hall sensors is prototyped. The magnetic field data are picked up by the National Instruments PCI 6255 data acquisition card.The results from the simulation and measurements are presented and compared in the paper. The study helps to design the electrode sensor arrays of EM flow meter. In addition to this, the distribution data of magnetic flux density are useful for the improvement of accurate flow rate measurement of EM flow meter.