Double-loop zero-flux transient electromagnetic detection device

Abstract

The invention discloses a double-loop zero-flux transient electromagnetic detection device, and relates to the field of geology and exploration geophysics. The double-loop zero-flux transient electromagnetic detection device comprises a transmitting coil, a transmitter and a receiving coil, wherein the transmitting coil is used for generating a primary pulse magnetic field and adopts a double-loop structure; the transmitter is used for supplying power to the transmitting coil; and the receiving coil is used for receiving a secondary induction eddy current field caused in the underground medium during the intermittent period of the primary pulse magnetic field. Compared with the prior art, the device has the beneficial effects that the transmitting coil in the scheme adopts the double-loop transmitting coil, the receiving coil and the transmitting coil are vertically arranged and coincide in center, the magnetic flux of a primary field in the receiving coil is zero, the mutual inductance influence between the transmitting coil and the receiving coil is eliminated, the receiving coil observes a pure secondary field, the detection blind area is reduced, and the detection precision is improved; and the secondary field directions of geologic bodies on the two sides of the coil are opposite, so that geologic anomalous bodies on the two sides of the transmitting coil can be distinguished.

Description

technical field [0001] The invention relates to the field of geology and exploration geophysics, in particular to a double-circuit zero-flux transient electromagnetic detection device. Background technique [0002] Transient Electromagnetic Method (TEM) is a time-domain artificial source electromagnetic detection method based on the principle of electromagnetic induction. It is a geophysical method that uses ungrounded return wires or grounding wires to launch a primary field underground, and after the primary field is turned off, measures the secondary field induced by the underground medium over time to find various geological targets. Exploration methods. The small loop transient electromagnetic method generally uses a multi-turn square loop source with a side length of less than 3m for detection. Compared with the large loop, the small loop transient electromagnetic method has been widely used in special operating environments such as shafts, tunnels, and mountains bec...

AI Technical Summary

Problems solved by technology

After the primary field is turned off, the secondary field will be excited on both sides of the transmitting coil (front and rear of the roadway, or the direction of the top plate and the bottom plate), and the direction of the secondary field of the geological body on both sides of the coil is the same, which cannot be distinguished, which reduces the detection accuracy

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