Frequency-offset method to determine conversion coefficient of extremely low-frequency magnetic field detector

This paper proposes a frequency-offset method to determine a conversion coefficient of an extremely low-frequency magnetic field (ELF-MF) detector to measure the strength of a power-line magnetic field, which is caused by electricity operating at 60 or 50 Hz. Using the frequency-offset method, the conversion coefficient can be determined in spite of interference caused by ambient noise. The frequency-offset method in this paper can be effectively used to develop an ELF-MF detector in a ambient noise environment.