The modern equipment and the technology used to locate buried cables are both very efficient and divers, allowing technicians to accurately identify the location of cables, as well as their potential faults.
Short description of an underground cable locator
These devices are able to detect not just cables, but also power lines, telephone lines, pipes and other buried systems. Typically they are user-friendly, lightweight, durable, using digital signal processing to improve detection accuracy.
How does it work?
The basics of the locating process didn’t change that much over time. Underground cable locators consist in a transmitter that must be turned on and a hand-held receiver that is waved over the area where the technicians are looking for buried utilities, picking signals. As soon as a signal is detected, it is displayed on the window at the top of the receiving unit and technicians must use their expertise to pinpoint the exact location of the cables, by following the electromagnetic field present around it. They can determine not just the cable’s location, but also its direction, depth and amperage of the signal.
You can find several types of underground wire locators: hum devices, radio frequency detectors, transmitter-receivers, or metal detectors. Some of them are equipped with various features that enhance detection capabilities in different circumstances. For example, some transmitters have a built-in voltage meter, which offers information on potential cable faults.
Both the transmitter and the receiver are placed in cases resistant to different weather conditions and can be powered by batteries, which assures their mobility.
For proper functionality, an underground wire locator must be used according to the instructions provided by the manufacturer; it should also be maintained and checked regularly.
Detection methods used by underground cable location specialists
- Electromagnetic Utility Locating
This is probably the most common locating method, which involves generating an electromagnetic radio frequency and applying it to the ground. This way any buried utility containing conductive material will generate a signal on the receiver and therefore will be able to be detected. On the other hand, if the utility contains materials such as concrete, unmarked plastic or asbestos, they will remain hidden. Another limitation of Electromagnetic Utility Locating consists in the fact that it doesn`t work too well beyond the depth of 10-15 feet.
- Ground Penetrating Radar
This method uses high-frequency pulses. Radio waves emitted into the ground are waved back up by buried facilities and allow displaying the objects on the receiver`s window. Although it has some limitations, this method is very efficient (it is typically used where other methods fail) and requires extensive training and experience.
- Acoustic Pipe Locator
This is another popular method that works well in soil, concrete and asphalt, requiring no system access and being easy to interpret. It consists in sending pings into the earth and monitoring the acoustic wave pattern, until having a locating profile.
These methods are based either on a passive signal (the signal that naturally occurs around a conductor) or on an active signal, which is generated intentionally, by a transmitter, to conductive cables or other utility lines.