- Locate earth leakage
- Locate depth to underground cables and pipes
- Locate underground cables and pipes
- Estimate current in cables and pipes
- Utility marker locators
The cable and pipe locator works by detecting electromagnetic radiation emanating from underground metallic pipes or cables. The system can detect services either passively (by detecting signals that are present in the utility itself) or actively (by detecting a very low-frequency signal induced into the utility). An inducer is used to generate the active signal into the utility by direct connection or by indirect electromagnetic coupling. The effective investigation depth with this technique is typically two metres with depth accuracy of +/- 20 % (accuracy is significantly reduced with increased depth).
The cable and pipe locator scanning is typically undertaken across a site in both passive and active detection modes. Direct induction will be used if there is access to exposed services. Typically services will first be traced starting at service pits locations and accessible service points such as taps and above ground conduits. This will often allow the traced service to be identified.
The technique cannot detect non-metallic utilities such as concrete, clay and plastic pipes; and fibre optic cables. Sometimes such utilities can be detected if they have been laid with a tracer wire or by inserting of a signal transmitter (sonde) into the pipe and tracing this transmitter from the surface. The technique may have difficulty differentiating different utilities in areas where many utility cables and pipes run close together in parallel. Concrete reinforcement within the pavements and slabs can often produce similar signals to utilities or can mask utilities buried below.
Data analysis and presentation
Utilities can be marked on site and / or presented on CAD drawings