GeoSearch Services, LLC uses both electromagnetic induction (EM) and ground penetrating radar (GPR) technology to locate and map buried underground utilities. Each method has its pros and cons and are meant to compliment one another. A thorough job of buried underground utility locating cannot be completed without the use of both technologies.
Electromagnetic Induction Technology
Standard EM locating equipment is great for locating most telecom, electrical, and gas lines but it has many limitations, especially non-metallic lines or non-conductive lines. Another problem with standard EM locating include sites where multiple lines are laid next to one another causing the target signal to "bleed" onto non-target lines. Additionally, standard EM locating equipment is easily affected by background signal interference and cannot detect other buried utilities or structures.
There are two methods to use EM induction technology. Conductive or direct methods are used when access to a metallic surface and proper grounding is possible. When direct access is not possible, the induction or indirect method is used. A signal can be induced into the ground above the utility with the transmitter or an inductive clamp can be used to send an EM signal into the underground line. The induction method is not as accurate as the conductive method but it is a great tool when used properly on some of the more challenging locates.
Ground Penetrating Radar Technology
The benefit of GPR technology is that it can locate metallic and non-metallic objects such as PVC, fiberglass, concrete and any other non-metallic material. The capability of GPR to “see” any type of object buried underground is essential in performing accurate utility locating and mapping. The most common method of locating buried tanks, drums and other buried lines is “pot-holing” or excavation, which is time consuming, costly and potentially dangerous. GPR technology is completely non-invasive and safe.
However, like EM technology, GPR also has limitations. Subsurface soil materials composed of high amounts of clay and/or saturated soil materials greatly limit the effectiveness of GPR. Other limitations include very small utilities, very round surface conditions or obstructed areas.
The limitations of both technologies need to be considered for each site and the best option or a combination of techniques can be used to locate the buried utilities We can work with you to help you determine how to complete your job safely, timely and cost effectively!
Private Utility Locating in Montana
Ground Penetrating Radar in Montana