| 摘要 |
Eddy current type metal detector for locating and distinguishing between different classes of metal objects, and geophysical apparatus for measuring various properties of soil and rock. A nonsinusoidal transmit voltage energizes a transmit coil which transmits a nonsinusoidal alternating magnetic field into the soil, rocks or metal objects to be located. Distortion of the magnetic field caused by the presence of these materials in the field induces corresponding voltage waveforms in a receive coil. The induced waveform is analyzed in order to deduce certain electrical properties of the materials, or in order to distinguish buried metal objects from the soil in which they are buried. The circuit which energizes the transmit coil returns energy from the collapse of the magnetic field to the power supply, minimizing the power consumption of the apparatus.
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