Geotherm provides in-situ Thermal Resistivity testing of the native soil where an underground electricity cable is planned to be buried. The testing is generally required to be carried out prior to cable installation. The values obtained from the testing will aid with the design of the cable system.
Geotherm can conduct Thermal Resistivity testing from a number of excavation methods. Primarily, using an open pit excavation allows Geotherm full access to the desired depth in order to conduct the in-situ testing and collect samples for laboratory testing. Testing can be conducted at various depths of the test pit if required, and can be conducted in sands, clays and soft rock. Some solid rock can be pre drilled to allow testing.
If an open pit excavation is not a feasible option, Geotherm can conduct Thermal Resistivity testing in auger/bore drill holes.
The in-situ Thermal Resistivity testing provides a result at the time of the test in units Kelvin meters per Watt (Km/W), as well as provides the ambient ground temperature.
To ensure a complete thermal survey of the proposed cable route, Geotherm conduct further Thermal Resistivity testing in the laboratory on the samples collected from each of the in-situ test locations. These samples are subject to a dry out process to allow analysis of the soil TR over a range of moisture contents. The critical moisture content is determined and a ratings design value obtained.