Whole-course transient electromagnetism synchronous depth sounding device

Abstract

The invention discloses a whole-course transient electromagnetism synchronous depth sounding device. The device comprises a transmitting coil, double-receiving coils and a multichannel receiver which is matched with the transmitting coil and the double-receiving coils. The double-receiving coils are composed of the first receiving coil and the second receiving coil, the second receiving coil is located in the first receiving coil, the first receiving coil and the second receiving coil are located in a same plane, and the common midpoint type is adopted; the transmitting coil is located on the peripheries of the double-receiving coils. The transmitting coil and the double-receiving coils are combined in a common midpoint mode or a common center shaft mode, and gaps are reserved between the transmitting coil and the double-receiving coils. According to the device, the signals of the transmitting coil and the signals of the double-receiving coils can be synchronously collected. The size of the transmitting coil is larger than the size of the receiving coils, the mutual inductance influence can be reduced, and the signal to noise ratio and sensitivity can be improved. By the adoption of the double-receiving coil-double channel synchronous measuring device, field signals in the later period and field signals in the early period can be effectively measured respectively, on the basis of ensuring mid-depth layer detectivity, detecting blind zones are reduced, and the superficial zone detecting effect is improved. A traditional center loop line measuring device type is unchanged, and the device is convenient and quick to detect and construct.

Description

[0001] technical field [0002] The invention relates to a transient electromagnetic full-depth measuring device, in particular to a full-range transient electromagnetic synchronous sounding device. [0003] Background technique [0004] The transient electromagnetic method belongs to the time-domain electromagnetic method (TEM), which is a time-domain artificial source electromagnetic detection method based on the principle of electromagnetic induction. Using an ungrounded loop (magnetic source) or a grounded line source (galvanic source) to send a pulsed magnetic field underground, under its excitation, the induced eddy current excited in the underground geological body will generate an induced electromagnetic field that changes with time (secondary Field), according to the characteristics of the quadratic field attenuation curve to judge the electrical properties, scale, and occurrence of underground geological bodies (citation: Niu Zhilian. Principles of time-doma...

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Problems solved by technology

[0005] For the time domain, the detection depth is determined by the time of observation. At present, almost all the late signals are recorded by TEM instruments, or only late signals are used in data processing. This situation will have two consequences: first , it loses the ability of the TEM method to detect the shallow structure, because the information of the shallow structure is mainly carried by the early signal; second, it reduces the resolving power of the TEM method, because the influence of the current shutdown will distort the transient response , therefore, in the actual measurement, people discard the distorted early signal, and only record the late signal after this moment, the effective detection depth is only below the depth that the signal can propagate at this moment, and there is a detection blind zone

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