METHOD OF CONTROL OVER STATE OF ROCK MASS Russian patent published in 2001 - IPC

FIELD: ore-mining industry. SUBSTANCE: invention can be used for contactless downhole induction control over state of rock mass and its technological parameters in process of mining operations, specifically, for control over jointing, water content, mineral composition and stress. Method enables accuracy of control to be increased thanks to higher level of measured signal in range of specific electric resistance of rocks up to 200.0 Ohm m. Inductance of generator coil in working range of change of specific electric resistance of mass is measured. Value of capacitance through which coil is connected to generator to form series resonance circuit is found by maximum value of inductance. Method of winding of generator coil in which current changes monotonously within working range is employed. Value of emf of secondary magnetic field of eddy currents is measured. Location, dimensions of anomalous zones and technological parameters of rock mass are evaluated by comparison of measured values with reference values. EFFECT: increased accuracy of control over state of rock mass. 2 dwg, 2 tbl