Transient Electromagnetic Method (TEM) is a
kind of time-domain electromagnetic method , which uses ore and underground
water’s conductivity and magnetoconductivity difference as main substance base,
then applies non-earthing loop or earthing line source to send first pulse
magnetic field to ground according to electromagnetic induction theory; Then in
the gap uses coil or earthing electrode to observe second eddy field, and also
study the space and time spread laws to search underground water and solve
other geological problems.