Problemy równoważności i interpretacji oraz wyboru rozstawu pomiarowego dla elektromagnetycznych sondowań częstotliwości nad izolującym podłożem oddzielonym od nakładu warstwą obniżonej odporności

Abstract

PROBLEMS OF EQUIVALENCE, INTERPRETATION AND SELECTION OF MEASUREMENT DISTANCE FOR ELECTROMEGNETIC FREQUENCY SOUNDING ABOVE AND ISOLATING SUBSTRATUM SEPARATED FROM OVERBURDEN BY A BED OF LOWERED RESISTIVITY Summary It was proved on an analysis of the functions (1-4) shown of Figs. 1 and 2 that for the cross sections of H-type (in the intervals of practical changes of magnitudes V, M) the equivalence principle (for constant current) does not exist in the classical notion. A conclusion presented in the paper illustrates the comparison of Fig. 2 with Fig. 5 (the last one reveals, for constant current, a characteristic inclination of isolines at an angle of 45°). A visible multiformity of solutions of the functions (3-4) shown on Fig. 2 excludes any introduction of functions (1-2) on Fig. 1. A solution for interpretation of three-layer and multilayer cross sections may be obtained by introduction of functions (5-6) on Figs. 3 and 4, and by putting the magnitude S along the right asymptote. Examples gives by means of nomograms are presented on Figs. 6 and 7. On the basis of the material here examined the author stresses a high value of the frequency sounding method in prospecting works, simplicity and exactness of the proposed technique of interpretation, and practical possibilities of reduction of sounding point distances.