METHOD FOR MEASURING A MAGNETIC FIELD USING MAGNETOELECTRIC SENSORS

摘要

The invention relates to a method for measuring a time-variant magnetic field using a magnetoelectric sensor having mechanical resonant frequency fR, wherein the magnetic field comprises at least one component having harmonic time dependence with the measuring signal amplitude to be determined Hmess0 and the measuring signal frequency to be determined fmess in a known frequency interval fmin mess max, characterised by the following steps: a. superimposing the magnetic field with a modulation magnetic field having harmonic time dependence with the known modulation amplitude Hmess0 and a selectable modulation frequency on the sensor, b. varying (wobbling) the modulation frequency over a complementary frequency interval determined by the known interval limits fmin,fmax and the resonant frequency of the sensor, c. measuring the sensor signal for each selected modulation frequency, d. searching for the at least one modulation frequency fmod, which results in a sensor signal in the mechanical resonance of the sensor, e. calculating the measuring signal frequency fmess from the previously determined modulation frequency fmod and from the resonant frequency of the sensor fR, f. transmitting the sensor signal at the modulation frequency fmod into the superimposed magnetic field amplitude Hsup, and g. calculating the measuring signal amplitude Hmess0 from the superimposed magnetic field Hsup and the modulation amplitude Hmod0.