INDUCTANCE METHOD FOR ELECTROMAGNETIC MONITORING OF SOIL THAWING PROCESS Russian patent published in 2000 - IPC

FIELD: electromagnetic methods for soil investigation. SUBSTANCE: method may be used for measuring electronic conductance and polarization characteristic of frozen soils in natural conditions. Method involves excitation of alternating electromagnetic field by means of horizontal frame, measurement of horizontal field constituent H_H and vertical field constituent H_Z at several frequency levels within range of tens to several hundred kilohertz, and use of ratio H_Z/H_H for measuring ground electric resistance ρ. Value of H_H for all working frequencies f₁,f₂,...,f_i,...,f_N is measured after compensation of primary magnetic field constituent H_H,O for lowermost working frequency f1. Then, method involves measuring increment Δ(lgρ) = lgρ_i+1-lgρ_i and monitoring process of soil thawing using temporal variation of ρ_i and coefficient K_f= Δ(lgρ)/Δ(lgf). EFFECT: increased precision of measurement of geological medium resistance and additional measurement of polarization characteristics of medium. 4 dwg