PQWT TC700 Geophysical Underground Water DetectorPQWT TC700 Geophysical Underground Water Detector Depth: 600 meters (1968 ft) PQWT TC700 automatic mapping water detector is based on the Earth's electromagnetic field as the field source, based on the difference in the conductivity of different underground geological structures, and by studying the variation law of the electric field components at different frequencies to study the geological structure and changes, to find groundwater resources by