A Device For Eliminating Transient Electromagnetic Primary Field

Abstract The present invention relates in particular to a device for eliminating the transient electromagnetic primary field, belonging to the technical field of the transient electromagnetic method (TEM). The device comprises a transmitter and a transmitting coil; the transmitting coil comprises two or more equally long transmitting coil segments; the two adjacent endpoints of each pair of adjacent transmitting coil segments are respectively connected to the two power lines at one end of the twisted pair; the other end of the twisted pair is connected to the transmitter. The primary field induced voltage pulse width of the TEM receiving coil can be greatly shortened from the traditional hundreds of s to tens of s under the method provided by the present invention, which provides an ideal device to eliminate the transient electromagnetic primary field for TEM exploration. Theoretically, the more the transmitting coil is divided, the better the elimination effect of the primary field is. At the same time, the present invention can also be applied to the frequency sounding of magnetic dipoles because the response speed of the transmitting current is greatly improved after the coil is divided. Drawings