A Quantitative Model for the Sensitivity of Untuned Voltage Output Fluxgate Sensors

In this paper, a quantitative model for describing the sensitivity of fluxgate sensors is presented. The model, which is illustrated by introducing the periodically changed apparent permeability as a periodic function, can accurately predict the sensitivity of fluxgate sensors. Compared with the previous works, the sensitivity of fluxgate can be predicted more simply and accurately. The model is verified by measuring the time-varying apparent permeability of a permalloy ring core. Sensitivity of a ring-core configuration fluxgate and a Föster configuration fluxgate is measured. The experiments results validate the model furthermore. The model can be applied to describe the sensitivity of other configurations by modifying the apparent permeability formula in the model. This method provides a new avenue to study the sensitivity of the fluxgate sensors.