Ground Penetrating or Probing Radar (GPR)

 

 

 

We utilise the latest GPR equipment from MALA to assist in the identification of non metallic subterranean utilities (or utilities that do not have a "carrier signal").
 
We have a variety of transmitters operating on different frequencies. Each frequency gives a different "imaging" depth.

 

In addition to the location of buried services, we have also used GPR to search for near surface cavities in Limestones and (in conjunction with a Mackintosh Probe) to determine variations in peat overburden thickness.

 

Radio Detection (RD)

 

Metallic pipes, cables, and services such as high pressure gas mains and strategic pipelines that have a carrier signal are located using the latest equipment from RadioDetection.

 

Where multiple circuits cross a site it is possible to isolate each one in turn by inducing a given frequency current onto a single utility and tracing that circuit based upon its known induced current signature.  It is also  possible to determine the depth to the utility as the reduction in signal strength is by a known constant.

 

RadioDetection should not be confused with 'CAT' scanning which is a 'Cable Avoidance Tool' and will only indicate if a utility is present.
 
 

 

 

Drains and Culverts

 

Non metallic pipes, drains and culverts are located by inserting a flexible cable down the utility and inducing a signal from a portable generator.  This signal is traced on the surface by the RD equipment.

 

As with the above situation, if the induced current is known then the depth to the utility can be determined.

 

In some instances the GPR can also be used to locate non-metallic pipes and culverts.  However, if the back-fill material is the same as the surrounding medium this may not always be possible as GPR requires a significant change in density to produce a clear image.