Invention of inductive magnetic sensor used for superficial layer CSAMT (controlled source acoustic magnetotelluric) method

Abstract

The invention relates to an inductive magnetic sensor used for a superficial layer CSAMT (controlled source acoustic magnetotelluric) method, which solves the problem of collection of magnetic field signals in a CSAMT observation method with working frequency of 10KHz to 100KHz. Multiple circles of enameled wire coils are wound on a long and thin magnetic core with high magnetic conductivity so as to induce the magnetic field signals to be tested and send inductive signals to a low noise amplifier for signaling, thereby obtaining voltage signals in an observable range. The whole sensor is realized in a magnetic current negative feedback mode. The magnetic current negative feedback feeds output signals back to an input in modes of a feedback resistor and a secondary coil so as to increase the working bandwidth of the coil and enhance temperature stability and mechanical stability of a system. The practice proves that the inductive magnetic sensor has the advantages of low noise, flat response functions and the like and is suitable for CSAMT engineering application.

Description

technical field [0001] The invention is the core component of a controllable source magnetotelluric sounding (CSAMT) instrument whose detection depth is between 0 and 100m, and mainly solves the problems of large volume, poor adaptability and poor stability of the magnetic field sensor of the current shallow CSAMT method. It can be used in fine engineering geological surveys, underground karst cave distribution surveys, large-scale water conservancy engineering geological surveys, and large-scale building foundation explorations. Background technique [0002] With the rapid development of my country's national economy, the implementation of major projects is increasing, such as building high-rise buildings, building high-speed railways, and large-scale water conservancy projects. In this process, it is particularly important to understand the fine geological conditions of the project area with an underground depth of less than 100 meters, such as the distribution of karst ca...

AI Technical Summary

Problems solved by technology

As one of the electromagnetic methods, the CSAMT method has a wide range of applications. At present, the CSAMT method is mostly used in the exploration of mineral resources in the range of 200 to 1000 meters underground, but it is not ideal for the resolution of 100 meters in the shallow layer. The reason is that Lack of magnetic field sensors with a receiving frequency in the range of 10KHz to 100KHz

At present, there are many magnetic field sensors with a working frequency below 10KHz in the market. Sensors above 10KHz generally have disadvantages such as poor signal response, bulky size, and inconvenient portability.

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