Radiofrequency (RF) path marking offers several unique benefits that set it apart from traditional utility marking methods. These advantages are especially valuable in congested underground environments, where accuracy and reliability are critical.
RF path markers are not susceptible to corrosion, cuts, or breaks in continuity. In the event a marker is damaged, the remaining markers continue to function. The markers also do not require a power source other than the locator used to identify them.
RF path markers offer the ability to distinctly identify a utility type by the frequency used. This adds an extra level of assurance when lines are located near one another.
The frequencies used:
RF path markers are not prone to “bleed off” which can occur from neighboring utilities’ tracer wires or other metallic objects, such as fences.
The installation of path markers embedded in tape is simple. Once the tape is laid in the trench, it does not require grounding, splicing, or any other costs or labor typically associated with tracer wire installation. Path markers also do not require any additional upkeep.
Common Ground Alliance (CGA) includes path marking guidelines in their Best Practices (Version 21.0).
Point markers (such as marker balls) are intended to mark specific features such as valves or bends, while path markers should be used to trace a utility’s overall route. Path markers are placed every eight feet. They are also oriented to indicate the direction of the utility path, helping the locator find the next marker. Point and path markers use two separate sets of frequencies to avoid confusion:
RF path marking is offered in two products by 3M, which are manufactured by Damage Prevention Solutions:
RF path marking offers reliable, efficient utility identification in congested underground environments. Benefits include resistance to corrosion and breaks, use of distinct frequencies for each utility type, and simple installation without grounding or splicing. These features make RF path marking an effective solution for the increasingly congested underground right-of-way.