In both urban and rural areas, there is an increasing network of underground utility lines. To prevent damage to these lines by digging, as well as to make it easy to locate the lines, most utility companies now use some form of EMS or electronic marker system.
There are several options for both above ground as well as underground marking of utility lines and systems. Each utility typically has their own combination of marking strategies that make it a simple task for their crews to be able to locate lines to mark them for construction and digging consideration, as well as to find them in the event of a problem or repair need.
The above ground types of markers can include tape, stakes, and rope, as well as stakes and paint. The choice of electric underground utility markers is often a function of the depth the line or cable is underground as well as the need for specific marking and identification requirements from the surface.
Full Range Markers
One of the most complete options in underground utility markers is the full range marker. This is usually used to identify key locations of the line or pipe, including valves, tees in the line, and other similar types of essential structures. These markers have a pre-programmed serial number that is sent out with the signal return, allowing for the precise location of key structures in the system. The ball marker is another type of full range marker. It has the added benefit of always maintaining an upright position even if the surrounding soil is moved.
Near Surface Markers
For marking lines close to the surface, the near-surface underground utility markers are ideal. They can be used in any type of material, including concrete and asphalt as well as soil.
These are small devices and can return the signal about three feet. They are cost-effective to install and have a long life cycle, even in outdoor conditions.