Utility contractors all want the same thing from their utility locating equipment: accuracy and efficiency. To that end, it’s important for contractors to look for features and innovations that help them locate their utilities safer, faster and more consistently.
First and foremost, a utility contractor must think about the specific type of underground object they are trying to locate.
A magnetic locator will locate ferrous metal objects. "These locators will find anything a magnet will stick to," says Scott Rauen, sales manager for SubSurface Instruments. "In the gas industry, contractors use them to locate things like valve covers, test point covers and manholes that might get buried."
A magnetic locator, however, will only come in handy when searching for metal. “An all-materials locator will find anything, including PVC pipe,” Rauen points out. “These locators are popular with contractors in the water, wastewater and natural gas industries.” SubSurface’s AML models utilize patented radio wave technology to locate underground objects.
Electromagnetic locators are also popular with utility workers. These locators detect the magnetic field around a utility system that is produced by a radio frequency. That radio frequency can occur naturally (passive locating) or via induction by a transmitting device (active locating). Subsite Electronics, which is part of the Ditch Witch division of The Toro Company, offers two electromagnetic locators, the UtiliGuard 2 and the 830R/T.
Rauen says SubSurface Instrument’s six-model line of pipe and cable locators are also big movers in all segments of the utilities industry. The PL-TT, though well-constructed and built with plenty of modern-day technology, is more of a budget-friendly locator for contractors only requiring intermittent use. The PL-G is a specialized locator, geared toward the oil and gas industry. The PL-2000 is ideal for the water industry. But when it comes to segments including electric and natural gas, Rauen says the PL-VF models are well-suited.
"The PL-VF3, in particular, is about our biggest seller right now," Rauen points out. "But for anybody having to find secondary faults in their electric wires, I typically recommend the PL-VF10. That gives the contractor 10W power output as opposed to 3W."
Ground-penetrating radar (GPR) is another type of utility locating equipment. Chris Thompson, senior product manager at Subsite Electronics, says this type of technology has been around since at least the 1980s. But like everything else that is technology-driven, it continues to improve.
“Our 2550GR machine is most helpful in locating plastic that you couldn’t put an electromagnetic signal on anyway,” Thompson points out. “We’ll also see utility contractors use it for what they call a pre-sweep. A contractor will call in a ticket saying that an area is clear. But the really good contractors will go out and pre-sweep with a GPR to make sure nothing was missed in the intended path.”
GPRs work by inducing a radar signal into the ground. That signal bounces back, telling the contractor if they are hitting something in the ground.
“GPR is a very job-specific technology in that the contractor must be working in conductive soil,” Thompson explains. “GPR will not work well in soils like wet clays. But in places like Florida and along the Gulf Coast in Mississippi, utility contractors have a lot of success with this type of machine.”
Thompson says there are some tricks of the trade to help maximize the performance of a GPR machine. “It’s important to use a good laptop with a Cat 5 connection so you can get the best picture on your screen,” Thompson says.
Durability and reliability
Utility contractors work hard, and they often work in harsh environments. Utility locating equipment must be built to meet the everyday conditions it is most likely to encounter.
“We understand contractors throw these things in the backs of trucks,” Thompson relates. “That’s why we drop-test all of our locators. Our locators are also IP65-rated to protect against dust and water intrusion.
“But I would say that above all else, it’s so important that we have an incredible network of dealers through the Ditch Witch organization,” Thompson continues. “In the rare event that there is an issue, the dealer will be right there in the field to help figure it out.”
Smart engineering helps keep those rare events to a minimum.
The AML PRO Series of all-materials locators from SubSurface Instruments, for example, features a durable ABS housing. ABS is a type of plastic known for its resistance to impacts and chemicals, and for its superior strength and stiffness. ABS also has excellent electrical properties.
The ML-3 and ML-3L magnetic locators from SubSurface are also built for durability. They are housed inside of an aircraft-grade aluminum mono-tube. "One of these locators could be run over by a 10,000-pound vehicle, and then start locating again when you pick it back up," Rauen says.
The ML-3 and ML-3L are also 100% waterproof. "Water and electronics usually don't mix," Rauen says. "When rain starts working its way into a unit, circuit boards start shorting out. With a waterproof locator, as long as you keep the battery compartment tight, you shouldn't have any issues with water."
Ease of use for Utility Contractors
Subsite’s Thompson says ease of use is another essential benefit for utility contractors.
Multi-frequency electromagnetic locators, such as Subsite’s UtiliGuard 2, give the utility contractor added flexibility. “For instance, if you have a pipe with numerous joints in it, or maybe a cable where there’s some noise in the area, you can switch to a frequency that will allow you to mitigate the noise and still pick up the line,” Thompson explains.
On the other hand, single-frequency locators can also provide an advantage in certain situations.
“We’ve found that utility contractors really like our 830R/T when working with gas lines,” Thompson relates. “I’m not sure what the particular properties are with those lines, but contractors tell us the 830R/T is very efficient in finding them. In fact, this unit works so well that we’ve actually made a locator that will broadcast on an 830 only. The advantage is that because the antenna is tuned to 830 only, you get a lot clearer broadcast.”
With any electromagnetic locator, the user interface is an increasingly important item to consider — especially as the workforce continues to change.
“Many of the people who are doing locating today are younger and familiar with various types of digital screens,” Thompson says. “With our UtiliGuard 2, we’ve tried to mimic something similar to that — something that will light up and tell the operator when they have a good locate. We want to make that user interface as intuitive as possible.”
Thompson says a more intuitive user interface also helps address a unique characteristic of the utility locating industry.
“There are two broad categories of utility locating equipment users,” Thompson explains. “One is the professional who is working for an 811 service and is doing locates all day long. Then you have people who are working with utility companies, either trying to verify locates or perform locates on private property that might not be part of the 811 system. Those people are typically wearing five different hats in a single day. A more intuitive user interface requires a lot less training. Furthermore, it’s easier to remember how to use the equipment after not having used it for a while. It’s a lot like riding a bicycle in that once you learn how, you don’t really forget.”
Innovation in Utility Locating Equipment
An enhanced user interface touches on another design feature utility contractors should look for: technological innovation. Utility locating equipment, particularly electromagnetic locators and ground-penetrating radar systems, are “technological” by nature. But as fast as technology has evolved, equipment manufacturers have hustled to keep.
Subsite Electronics, for instance, has added GPS to its UtiliGuard 2. “Our GPS module is accurate to within 10 feet,” Thompson points out. “When you’re out locating, instead of having to look over a huge swath of area, you can log a GPS location. Then when you come back later, you know generally where it is.”
Sometimes a utility contractor would like to have accuracy that’s better than 10 feet. That is why Subsite has also added Bluetooth technology to the UtiliGuard 2. “If the utility contractor needs that really precise, 1 to 3 cm accuracy, they can pair the UtiliGuard 2 to other GPS providers that can provide that,” Thompson says.
One other feature upgrade that goes along with GPS functionality is logging and mapping. “We’ve put enhancements in the UtiliGuard 2 to support ArcGIS or any other kind of mapping a contractor wants to do,” Thompson says.
Even when armed with the best utility locating equipment, Thompson says a utility contractor’s biggest hindrance will always be safety. “When putting utilities into the ground, you absolutely have to miss what is already out there,” Thompson emphasizes. “That is why 811 is so critical to damage prevention.” In the utilities industry, a simple phone call might be the best utility locating equipment of all.
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