The measurement of transients of the electromagnetic field (TEM) is an active geophysical measurement method in the time domain that gives information about the electrical conductivity properties of the ground.
 

Measuring principle

A wire coil (typically several hundred meters) is laid out on the area under investigation.
The constant current in the transmitter coil induces a subsurface magnetic field. Is the current switched off does the collapsing primary field induce eddy currents in the conductive parts of the ground. This eddy current system in turn produces a secondary magnetic field, which is determined by the conductivity distribution. This secondary magnetic field is is measured by JESSY DEEP.
 

Application

TEM measurements are taken to gather geological information such as the detection of conductive (e.g. minerals) or resistive layers (such as gravel deposits). On the other hand, TEM measurements can contribute to the clarification of environmental questions such as finding waste deposites, polluted or contaminated areas.