The job required locating shallow PVC gas lines, recalls Matt Crosby, environmental scientist and business development rep at Master Locators in Philadelphia. Since the lines were nonmetallic, ground-penetrating radar (GPR) was used. But the Master Locators crew was still having difficulty seeing much of what was below the surface, especially with the moist clay soil hindering the GPR’s penetration ability. The 250 megahertz antenna on the unit was switched out for a 500 megahertz antenna. Suddenly the view belowground was much better.“Little changes like that can definitely help depending on the soils you’re working in,” Crosby says.It’s one example of
