METHOD AND DEVICE FOR GEOELECTRIC PROSPECTING Russian patent published in 1994 - IPC

FIELD: geoelectric prospecting. SUBSTANCE: electromagnetic field is excited in tested medium, sequence of current pulses is formed in loop I by generator assemble 2. Current pulse period is synchronized with period of industrial noise by means of synchronizing unit 5. Signals of transient process are received by detector 3; these signals are measured after each current pulse is discrete moments of time. Prior to any measurement the average value of preceding measurements is calculated in microcomputer 10. Analog compensating signal is formed in compensator 6 according to calculated average value. Compensating signal is calculated on the base of input signal by means of difference amplifier 4. Difference signal is integrated in specified time interval by several integrators 7 simultaneously taking into account different gain factors. Result being maximal of tolerant results of integration is determined by means of circuit 8 for choosing measurement scale; this result is transformed into digital form by analog-to-digital converter 9. Result of any measurement is calculated in microcomputer 10 in of sum of values: value of compensating signal which corresponds to set time interval, result of integration of difference signal in that time interval and value of low-frequency noise, corresponding to that time interval. EFFECT: enhanced precision. 2 cl, 2 cl, 10 dwg