Methods
The low-frequency magnetic flux density (B) was measured
using the Narda STS EFA-300 electromagnetic field
analyzer with its isotropic probes and measurement range
up to 31.6 mT [6]. The broadband filter of the instrument
was selected in the frequency range from 5 Hz to 32 kHz,
with an uncertainty of !3% for the magnetic flux density
measurement and !4% for measurement of the percentage
of the ICNIRP reference levels for the general public [6].