The Basics Part 1-2: Signal
Signal is a very important part of locating, an idea which should be fully understood before a student dives into the heart of the training program. Using video graphics and animation, we tried to visually demonstrate what signal actually does relative to the utility and the locating instrument. The best way to do this was to show how signal circles work. They are created by flowing alternating current on the metallic skin of a pipe or cable. These signal circles want to leave equally in all directions (Figure 5).