Real Time Monitoring of Weak Magnetic Field

This study describes a possibility of using magnetoelectric coupling effect to measure ultra-low-frequency weak AC magnetic fields. The research uses a composite structure composed of a PZT piezoelectric body with a size of
$\mathbf{25} \mathbf{mm} \times \mathbf{2}\ \mathbf{mm} \times \mathbf{0.5}\ \mathbf{mm}$
and an appropriate size of magnetostrictive material Metglas as a sensitive element. A Metglas/PZT-5B magnetoelectric coupled sensor with a mechanical resonance frequency
$\boldsymbol{f}_{\boldsymbol{r}}$
of 58 kHz was prepared. And a test system was set up to measure the weak AC magnetic field and display it in real time. This system uses the frequency up-conversion technique (FUCT) of ultra-low-frequency magnetic field, combined with hardware devices and software programs, for the magnetoelectric coupled sensor made by this test system, it can test the ultra-low-frequency weak AC magnetic field with a frequency as low as 0.1 nT @ 1 Hz.