Responsivity of Fluxgate Sensing Element Under Different Excitation Conditions

Fluxgate magnetic sensors measure weak magnetic fields in the range of 0.01nT to 1mT. They are one of the most used sensors in a wide range of applications because of their advantages over other types of sensors in a certain area of measured intensities and frequencies. The principle of operation of Fluxgate magnetometers is based on manipulating a nonlinear magnetic material as the sensing element to measure the strength of a surrounding dc or low-frequency ac magnetic field. During fluxgate design, the magnetic core is the most important element that determines the performance of the sensor. In this paper, evaluation of the response of the fluxgate core is done through numerical simulations under variable operating conditions. The fluxgate core is modeled using finite element method to involve the nonlinear hysteretic characteristics of the core into the conducted simulations. Thus, the proposed model helps to produce more reliable results about the behavior of the fluxgate sensing element. Furthermore, several simulations were conducted in this paper to provide a performance map for the fluxgate core that will help designers to choose the best operation conditions for the desired design.