Double-transmitting-coil transient electromagnetic combined device

Abstract

The invention relates to a double-transmitting-coil transient electromagnetic combination device which comprises a positive transmitting coil, a negative transmitting coil, a receiving coil, a transmitter and a receiver. The positive transmitting coil and the negative transmitting coil are electrically connected with the transmitter, and the receiving coil is electrically connected with the receiver. The receiving coil is located in the forward transmitting coil, and the reverse transmitting coil is located in the receiving coil. When the transmitter supplies power to the positive transmittingcoil and the negative transmitting coil, the current directions in the positive transmitting coil and the negative transmitting coil are opposite, and the magnetic flux generated by the positive transmitting coil in the receiving coil and the magnetic flux generated by the negative transmitting coil in the receiving coil are equal in size and opposite in direction. According to the invention, thetotal magnetic flux generated by the positive transmitting coil and the negative transmitting coil in the receiving coil is zero, the aliasing phenomenon of a primary field and a secondary field of aconventional receiving coil can be eliminated, the influence of mutual inductance is reduced, and an observed transient electromagnetic signal is enabled to accord with an actual law.

Description

Technical field [0001] The invention relates to transient electromagnetic equipment, in particular to a transient electromagnetic combined device with dual transmitting coils. Background technique [0002] Transient Electromagnetic Methods (TEM), also known as time domain electromagnetic methods, is a commonly used physical prospecting method. The working principle of this method is to pass a varying current to the grounded wire or ungrounded loop to the detection area. When the primary field is launched, the target geological body generates an induced current under the action of the primary field, and then a secondary field is generated. In actual work, the secondary field is often observed during the interval between the primary field. This method is mainly used in engineering geological survey, metal mine survey, coal mine survey and other fields. The existing coils mostly use overlapping loop coils, which have strong mutual inductance. Especially in the early stage, the ind...

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Problems solved by technology

Most of the existing coils use overlapping loop coils, and the mutual inductance is strong. Especially in the early stage, the induced electromotive force and the secondary field electromotive force are superimposed, and the measurement curve does not conform to the electromagnetic law of the secondary field, so the actual use effect does not match the actual geological conditions.

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