100m 500m 1000m Time Domain Transient Geophysical Tranisent Electromagnetic Survey Subsurface Imaging TEM Surveys for Groundwater And Mineral Exploration
Transient electromagnetic method (TEM) is a method to detect the resistivity of underground medium by using the coil or grounding electrode to observe the secondary induced eddy current field caused by the underground medium during the intermittent period of the primary pulsed magnetic field by using the ungrounded loop or grounding source to emit a pulsed magnetic field to the ground. Its basic working method is to set up a transmitting coil with a certain waveform current on the ground or in the air, so as to generate a primary electromagnetic field in the surrounding space, and generate an induced current in the underground conductive rock ore body: after power failure, the induced current decays with time due to heat loss.
Transient electromagnetic method, also known as time domain electromagnetic methods, referred to as TEM, is a method of using ungrounded loop or ground wire source to emit a pulse magnetic field to the ground. During the interval of a pulse magnetic field, the coil or grounding electrode is used to observe the secondary eddy current field. In short, the basic principle of TEM is the law of electromagnetic induction. The attenuation process is generally divided into early, middle and late stages. The early electromagnetic field is equivalent to the high frequency component in the frequency domain, with fast attenuation and small skin depth; The late component is equivalent to the low frequency component in the frequency domain, with slow attenuation and large skin depth. The geoelectric characteristics of different depths can be obtained by measuring the variation of secondary field with time in each period after power failure.
Standard configuration of WTEM-2 system:
WTEM-2J TEM Exploration System Receiver
WTEM-2D 10kw High-Power Transmitter
WTEM-2T/GPS Transmitter Synchronized Controller
Pocket PC (PDA) to control the TEM system receiver and the system.
Optional instruments:
PTT-40A Antenna & Adapter
| Power Supply: DC 4V~360V |
| Rated Output Power: 10Kw |
| Maximum Output Voltage: 360V |
| Maximum Output Current: 50A (continuous), 70A (pulse) |
| Frequency Range: Power Supply 1.25~125Hz (8 frequency spots) |
| Output Waveform: Two Types (Mode 0, Mode 1) |
| Shutoff Time: Change with transmitting current, transmitting coil when connecting coils |
| Minimum Shutoff ?Time: 1.2μs (pure resistance load) |
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