From top to bottom:
接收到的磁场强度曲线：
Received magnetic field strength
curve
磁棒线圈：
Magnetic coil
电磁接收头：
Electromagnetic Accept end
电缆：
Cable
磁力线：
Magnetic field lines
●
Trough method
test theory as shown.
When conducting path detection, make the magnet coil axis perpendicular to the
ground, and slowly move the coil. When the coil is located directly above the wire
and perpendicular to the cable, the magnetic field lines are parallel with the plane of
the coil. There is no magnetic field line going through the coil, so the induced
electromotive force in the coil is zero, so that you can hear nothing or lightest in the
