LIMITATIONS AND RESTRICTIONS

Ground Penetration Radar (GPR) is a non-destructive testing method and for that reason it has various limitations and restrictions.

The GPR concrete scanning unit has a maximum depth of 400mm in ideal conditions like concrete structures with minimal steel.

The depths that are collected for the located targets are an approximate and maybe slightly shallower or deeper than stated.

Targets are located by the centre of the GPR scanning units where the antenna is situated. The centre of the antenna needs to be able to roll over the target perpendicular, this means GPR data cannot be collected within a 100mm from any wall or obstruction on the concrete scanning unit and 400mm from any obstruction on the utility locating detection unit.

The GPR scanning units must have the wheels rolling in order to operate and collect data. There is a small gap between the bottom of the concrete scanning unit and the ground, which means the surface needs to be somewhat smooth.

The GPR scanning units cannot penetrate through metallic objects or through water.

GPR can locate voids however cannot image anything within or beyond a void.

GPR scanning units cannot establish the material or the diameter of the target/ object.

GPR concrete scanning unit cannot locate in slab services if they are below the steel reinforcement bars.

The 50Hz electromagnetic sensor and the pipe and cable locator cannot detect inactive or low voltage cables within the concrete structure, they must be energised at the time of the scan.

Locating electrical cables can only be accurate when connected and traced from a known point of existence.

The electromagnetic field can be broad when detecting an electrical current, this means when marking the location of the electrical cable will not be exact.

When scanning for services with the electromagnetic locator, the services can be within the concrete slab or below the concrete slab.

RECOMMENDATIONS

Star Scanning would recommend you have an appropriate distance away from any marked power, conduits, post-tension cables, unknown objects and beams when coring / cutting / drilling.

Check scanned areas against post-tension, electrical and structural plans before any destructive works takes place.

Locate the work area/s if penetrating through the concrete structure to identify the location on the level below, this can be done by using a Hilti px 10 transpointer or by drilling pilot holes.

Isolate the work area before any destructive works takes place.

DISCLAIMER

Star Scanning Pty Ltd shall not be liable for any damage, repairs or remedial works resulting in penetrating the concrete structure.

Star Scanning technicians are collecting and interpreting the GPR data for indicative purposes.

Star Scanning Pty Ltd are not liable and does not make the decision to penetrate the concrete or of the penetration locations.

Star Scanning Pty Ltd makes every effort to detect services,

however we advise pot holing to confirm sevices for a more accurate depth and description before any excavating works.