Brief Introduction To Transient Electromagnetic Method

Transient Electromagnetics Method TEM is based on the difference between the electrical conductivity of rock (ore) in the earth's crust and the magnetic conductivity of DAO. According to the principle of electromagnetic induction, a pulse magnetic field is sent underground by using ungrounded loop or ground wire source, during the gap of a pulse magnetic field In order to search for underground mineral resources or solve other geological problems, the time-domain electromagnetic method is used to observe the secondary eddy current field by means of coil or earthing electrode and study the spatial and temporal distribution of the field.

Theoretically, electromagnetic sounding can be performed in both frequency domain and time domain, and the two domains contain completely equivalent information. While the frequency domain operates over a series of discrete frequencies, a pulse in the time domain often contains an extremely rich frequency component, so there are still some subtle differences between the two.

Central loop

A device in which the large loop Tx transmits and the small loop Rx receives, and the center points coincide. Features: the anomaly features are the simplest, the lateral resolution is high, and it is greatly affected by the - - sub-field

Sounding exploration, from shallow to deep reflection.

Overlapping loop

Transmitting loop Tx and receiving loop Rx, mainly on - up device. Characteristics: the anomaly features are simple, the lateral resolution is low, and it is most affected by - - sub - field. It is suitable for mid-deep exploration.

Dipole device

Transmitting loop Tx- A certain distance from receiving loop Rx. Features: complex anomaly features, high lateral resolution, minimal influence by primary field, suitable for shallow central exploration.

Large fixed source loop

A device in which the transmitting loop Tx does not move and the receiving loop Rx moves within a certain range. Characteristics: complex anomaly characteristics, low lateral resolution, complex influence by - - sub - field, suitable for deep exploration.