Part 5 of this continuing series follows a thorough discussion of 3D Subsurface Imaging and utility mapping from the previous segment (Part 4) on utility detection, vacuum excavation work and its encompassing technologies. Examining other technologies in the segment that follows, author Carol Brzozowski discusses a company’s sophisticated instrumentation that utilizes ultra-high radio frequencies to detect buried utilities in Part Five of this ongoing series.
Hitting the Hidden Mark (Part 5) By Carol Brzozowski
The combination of the vacuum and utility locator help get that precise target.
Among the offerings of SubSurface Instruments Inc. is the All Materials Locator (AML), which uses advanced, ultra-high radio frequencies to locate buried PVC pipe.
The technology utilized by the AML was originally developed by NASA engineers for a 2004 space mission to Mars to examine the density below the surface, says Joe Weiland, company president.
The AML is designed to function in clay, wet soil, snow, or standing water without the need for a separate transmitter and receiver, wires, clips, or clamps.
It is typically used in the utility, water, gas, and cable industries.
The AML works as such: While holding the handle parallel to the ground, the user scans the area of the suspected pipe or buried object until one or both of the AML’s target indicators activate.
While the left or right target indicator is activated, the AML is rotated until both LED target indicators light simultaneously, triggering its tone and laser marker, indicating that the pipe or object has been detected and that the AML is then parallel with the underground object
With the AML in parallel with the pipe or underground object, the end user can scan the entire length of the object’s edge. An alternative approach is to utilize the ‘W’ method of scanning by sweeping the area in a back-and-forth ‘W’ motion to mark the object’s location and run direction as it is tracked.
“While no single locator works for every need, the AML complements pipe and cable locators and is the only locator to have in looking for undetectable products,” Weiland says.
At We Energies in Milwaukee, WI, Mark Sobon, operations supervisor for the damage prevention group, has 15 AML units. They’re used as a secondary tool.
“When we try to locate our gas utilities or our electric lines, we would go to a method of trying to get a signal off of our utilities,” he says.
The company will use an AML as a secondary tool to locate a gas pipeline, especially those without tracer wires. Sobon has used it to locate an 8-inch pipe in the outskirts of a landfill.
“Soil condition really doesn’t play a factor in it as far as more gravelly to clay soil,” says Sobon. “The only part it plays is if you go from a hard surface to a soft surface because it goes for density change. If you’re jumping from one surface to the next, you’ll have a difficult time, because a grassy area is going to be a different density from the road. But the ground and water and snow doesn’t play a part.”
