A Thermal Resistivity Probe measures the soils resistance to heat transport. The soil thermal resistivity is important in determination of cable ratings when burying power cables. This information is commonly used in wind farms. The thermal resistivity probe also reads the thermal conductivity of a soil, which is simply the inverse of the soil's thermal resisitivity. Thermal conductivity properties are often needed in construction of geothermal heatpumps. Testing procedural information is available in the following standards: ASTM D5334 and IEEE 442.