Watch has a component called gossamer, this thing is most afraid of watch in the magneticfield near a magnet, spring will be magnetized.
手表里有个部件叫游丝，这东西最怕的就是磁场，手表在靠近磁铁后，游丝会被磁化。
2
Based on the spatial distribution of magnetic dipole, the equation of the normal component of leakage magneticfield on the tube surface under low-intensity field was derived.
To measure the horizontal component of geomagnetism, the "bifilar balance method" is used, together with an additional adjustable magneticfield to compensate the geomagnetic field.