Two views of the real-time DGPS linked terrain electrical conductivity system are shown here. The first image shows the trailer-mounted system behind the survey vehicle. The second image shows the on-foot style of survey.
Survey production rates of 5 to 20 line-km per hour are possible with the trailer-mounted system. The survey operator constantly monitors the electrical conductivity measurements as they are recorded and can adjust the survey to detail areas of interest.
Figure 1. Truck towing an EM-31 on a trailer.
Figure 2. Truck towing an EM-38 in a custom built container.
Figure 3. EM-38 in a custom built container.
Figure 4. Snowmobile towing an EM-31 on a sled.
Figure 5. Snowmobile towing an EM-38.
Figure 6. The on-foot survey mode provides production rates of 1 to 4 line-km per hour. Again, the operator constantly monitors the observed electrical conductivity measurements and can adjust the survey immediately to detail areas of interest.
Figure 7. An on-foot EM-31 survey on a farm field.
Figure 8. Winter surveys allow quick and easy coverage over swamps, ponds, lakeshores, and ditches to provide a more complete survey.
Figure 9. The larger EM-34 system shown above works well in either summer or winter projects.
Figure 10. EM-34 survey in progress.
Figure 11. A comparison of two terrain electrical conductivity (TEC) surveys, in 1994 and the second in 2001 is shown above. The 1994 survey was done to assist in siting a landfill. A quarter section can be covered in 1 to 3 hours depending on the detail required, ground conditions, and weather.
Figure 12. A terrain electrical conductivity survey was completed around a waste water treatment lagoon to look for seepage. Just about every area of high electrical conductivity show above is related to seepage from the lagoon.
Figure 13. Interpreted geological sections from an area adjacent to a proposed wastewater treatment lagoon.
Figure 14. Terrain electrical conductivity survey induced current vs. depth.
Figure 15. Chart comparing electrical resistivities of common earth materials.
Figure 16. Table of EM-31 measurement densities for reconnaissance and detail surveys.