Fluxgate sensor has high sensitivity and temperature stability, small size and low power consumption. Fluxgate sensors can often provide very useful alternative in determining the location or position of a magnetic object, where other technologies cannot be used. For example, the GPR only, does not provide maximum results when used to characterize the magnetic material in the conductive subsurface or has a high reflectivity zone, but fluxgate sensors are capable. Characterization of magnetic materials in the soil subsurface is required. It is used as a proxy to determine the content of heavy metals and pollutants in the soil. In this work, we have carried out the development of fluxgate sensors for detection of magnetic material in soil subsurface. The fluxgate element consists of two pick-up coils, four excitation coils, and the ferromagnetic core. The highest sensitivity of fluxgate sensors that have been developed is 877 mV/µT and a maximum absolute error of 0.066 mV/µT. This paper will discuss the influence of the frequency of the primary magnetic field of the solenoid on the sensor response, the influence of soil magnetic susceptibility, and the effect of the presence of magnetic material in the soil subsurface to the sensor response.
Signals in the Soil: Subsurface Sensing