Application of EH-4 system in water inflow risk survey of mines

EH-4, belonging to device of mixed sources, is a frequency domain electromagnetic sounding system which combines man-made field source and natural field source. The special man-made electromagnetic wave emitter and the new type low noise magnetic unit are applied to combine man-made field source and natural field source, which makes it possible to survey part of man-made filed as well as natural field. Two semicircle antennas perpendicular to each other which are employed in emitting avoids the trouble of grounding as well as laying long emitting lead. Meanwhile the emitting-receiving distance is shortened to a large extent, which is convenient for filed work. Combining the advantages of both natural field and man-made field, this device, which boasts stability of CSAMT as well as flexibility and adequate survey depth of MT, is broadly applied. With EH-4 system, the water inflow risk survey of Shandong Laiwu Laixin Iron Mine proves to be effective and provides reliable information for the recovery of the water inflow risk for the mine.