By using the EMS markers during installation, construction and maintenance, the facility owner saves time when locating utilities. Markers are color-coded for visual reference to a particular industry (gas, communications, power and water/wastewater), as well as carry an industry-specific frequency.
3M Utility Markers
3M utility markers are passive antennas with no power source to drain. They're composed of a polyethylene exterior which is resistant to water, minerals, chemicals and varying temperatures typically found underground. The electronic marker operates even in the presence of metal, pipe, conduit, conductors, fences, AC power lines, and electronic markers of other utilities.