Some Problems in Old Mine Exploration Using EH4 Need to be Noticed and Discussed

摘要

EH4 is one of the most widely used device to detect metal ore in old mines.However,there are many issues worthy of in-depth analysis and discussion in practical application.So the authors make a preliminary analysis and summary of case review in the old mining problems.Firstly,according to the basic theory of magnetotelluric method and characteristics of time domain Ex,Ey,Hx,Hy,judgment of high frequency data and low frequency data is established.The influence of electrode distance,relative elevation electrode,dectrode grounding resistance,magnetic and electric field probe electrode holder angular deviation,and deviation angle of the magnetic sensor on the measurement results are analyzed.Then the measured time series data is converted to the fiequency domain by the FFT data and the Bostick resistivity is calculated.The effectiveness of EH4 is tested by several practical examples.Finally,the paper presents several suggestions for reference in practical application.