PURPOSE: To identify a background magnetic field and a local magnetic field and to measure it by correcting the variance of the sensitivity of a magnetic detecting element and calculating whole magnetic field intensity, background magnetic field intensity and local magnetic field intensity.
CONSTITUTION: The output signal of a magnetic detector 100, on which plural magnetic detecting elements S1 to Sq to detect a background magnetic field and a local magnetic field at the same time are provided, is processed at a signal processing circuit 200 and the processed signal is held at a sampling hold circuit 500 temporarily and is converted into a digital signal with an A/D converter 600. The converted signal is fetched by a computer through an I/O interface 700, the correction of the magnetic detecting sensitivity of the magnetic detecting elements S1 to Sq is executed with a standardizing means and whole magnetic field intensity impressed on the magnetic detector 100 is calculated with a whole magnetic field calculating means. Moreover, background magnetic field intensity impressed on the magnetic detector 100 is calculated with a background magnetic field calculating means and local magnetic field intensity impressed on the magnetic detector 100 is calculated with a local magnetic field calculating means.
TAKEUCHI SHINJIRO
SAKAI FUKUO
HARA KUNIHIKO
YOSHIMUTA KOZO
