PQWT TC500 Geophysical Underground Water DetectorPQWT TC500 Geophysical Underground Water Detector Depth: 500 meters (1640 ft) PQWT TC500 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