GSSI Profiler Brochure
Electromagnetic Induction (EMI). EMI instruments contain two sets of coils that are located on opposite ends of the tool. One set of coils is used to transmit a primary magnetic field, which generates an electrical current into the ground. The induced current then generates a secondary magnetic field, which is sensed by the coils in the receiver end of the instrument. The EMI is moved over the surface without coming in contact with the surface so it is not affected by the terrain. However, EMI results are affected by surface features including vehicles, reinforced concrete, and buildings and will not be used in the vicinity of above-ground obstructions. Data is then displayed on a control unit indicating the conductivity of the earth or buried objects. The data is post-processed and displayed in a color-coded contour map which shows relative changes in conductivity. This contour map will be provided by GPRS for interpretation by the client.