Russian

Application

Recording of electromagnetic processes in the Earth crust; geophysical exploration, tracing structural and lithological inhomogeneities; monitoring of geodynamic earth crust movement; express-evaluation of seismic risks.

 

Principle of Operation

Both the recorder and its applications are based on fundamentally new physical ideas on sources and triggers of natural pulsed electromagnetic field of the Earth (NPEMFE) in the ultra low frequence range. NPEMFE pulses arise in the Earth crust as a result of its continuous geodynamic movement. These pulses are recorded by MGR-01 at any point on the Earth surface. Structural and lithological inhomogeneities are sources of electromagnetic field. This idea makes grounds for using MGR-01 as a basic instrument for new method of geophysical exploration. Studying of geological structure and tracing perspective territories are carried out with two or several MGR-01 multichannel geophysical recorders. One recorder serves reference  (stationary) station recording time variations of electromagnetic fields. Other instruments measure NPEMFE on the routes  crossing the territory under study. Conclusion on presence or absence of structural or lithologic inhomogeneities is made  in the following way. From the readings  of the route stations we subtract time variations of the electromagnetic fields recorded  by the reference station.

 

Specifications

Application conditions for sensors - from -40 to +40 °C 

Two identical channels for measuring magnetic component of NPEMFE:

Sensor-ferrite-rod antenna with resonance frequency of 14.5±1 kHz;

Conversion coefficient from 0.058 to 58 V_xm/A;

Gain - from 20 to 84 dB;

Reference voltage on comparators - from 0.0012 to 2,5 V;

Channel for measuring electric component of NPEMFE:

Capacitive differential transducer;

Bandwith of amplification path - from 500 Hz to 200 kHz;

Intrinsic noise - 60 µV;

RAM capacity no less than 1Mbyte;

Period of data storage in RAM no less than 3 months;

Data exchange between the recorder and PC via RS-232 interface;

Supply from ac network (220±22) V or from accu,ulator (13.2±2.4) V;

Power consumption no more  than 5 W;

Weight no more than12.0 kg;

Sizes are determined by hermetic container 410x340x205 mm;

Possibility to connect up to 5 extra channels.

 

Merits

When solving  geophysical problems, the recorder combines merits of both electrical and seismic surbeys, asserts high sensitivity to rupturing deformations in the Earth crust, boundaries between dissimilar mucks including structures that are poorly distinguished by ordinary seismic survey.

High productivity, portability, and self-sufficiency of the instrumentation, possibility to work at hard-to-reach areas assert quick route survey over large territories.