An expert guide to utility locating
In the construction and utility sectors, accurately locating underground infrastructure is crucial for both efficiency and safety. At Spearhead Locating Services, we are dedicated to providing precise and reliable utility locating services that help our clients avoid costly delays and ensure the safety of their projects. This comprehensive guide answers some of the most frequently asked questions about our services, highlighting their importance and the benefits they offer.
How Do Ground-Penetrating Radar (GPR) and Electromagnetic Locating Differ?
Both GPR and electromagnetic locating are vital tools in our arsenal, but they serve different purposes. Neither one is a “do all” piece of equipment that can detect everything all the time. There are many factors and limitations to the performance of each and this article will help you understand the differences.GROUND-PENETRATING RADAR (GPR)
How It Works. GPR sends radio waves into the ground. These waves bounce back upon hitting an object, creating a subsurface image on the display screen. The GPR sends out the signal at only one speed and power, so in dry sandy soil the signal travels very fast and easy, hits the object and bounces back with a lot of energy, but in wet clay type soil the signal travels very slow and cannot penetrate very deep, so when it hits an object it has very little energy to bounce back, especially small deep objects.
Applications. GPR can be used in an array of applications, such as finding utilities, Underground storage tanks (UGST) and trenches to name a few we use it for.
Limitations. Performance can be affected by soil conditions, such as high moisture or heavy clay content, concrete or asphalt on top soil. Size and type of material the target object is made of and depth of the target object. All these factors combined determine if the GPR will be successful at giving a good result.
ELECTROMAGNETIC LOCATING
How It Works. This method uses electromagnetic fields to detect metallic utilities by inducing a signal on the utility and then detecting that signal with a receiver. Today’s electromagnetic locators are very sophisticated and have a wide range of frequencies that can be transmitted onto the utility. The reason for this is because not one frequency works on all utilities or conditions. What worked on one utility may not work on another, there are full day training classes just about understanding this topic, so we won’t get into that. But once you get a good signal it will travel down the length of the utility emitting that signal in a ring around the utility, the receiver picks up this signal as you scan over the top of the utility and can accurately find the horizontal position and depth of it.
Applications. Can be used on any conductive pipe or cable.
Limitations. Cannot be used for non-conductive materials such as PVC water lines or fiber optic lines. On conductive materials the signal may bleed over to nearby utilities and can struggle in congested utility environments.
What Types of Utilities Can Spearhead Locating Detect and How?
We specialize in locating a wide variety of underground utilities to ensure your site remains safe and efficient. Our advanced technology allows us to detect:
- Gas Lines. Steel or Polyethylene with trace wire. Steel lines can be detected with an Electromagnetic locator or by GPR because they are highly conductive and very reflective. If it is Polyethylene with a trace wire an electromagnetic locator is used, GPR would have a hard time seeing it under most conditions.
- Water Lines. Conductive and non-conductive. Depending of the material of the line, we have 3 methods to use, Electromagnetic, GPR and Acoustic, or a combination of these.
- Electric Cables. High voltage and low voltage. Because electric cables are so conductive, we almost exclusively use electromagnetic.
- Data Cables. Phone, cable and fiber optic. almost exclusively use electromagnetic for phone and cable, either GPR or a Locating Sonde for Fiber optic cables.
- Empty conduit. 1” or larger. Locating Sonde on a rodder.
By accurately locating these utilities, we help prevent costly damages, delays, and safety risks.
Your Locating Services Partner
With years of experience and expertise providing happy customers with a wide range of locating services, we’ve proven that one call and all your locating needs are covered.
Our flexible, professional, and customer-oriented approach to business means we’re there for you when you need us.
0 Comments