IEEE 442-1981

This guide covers the measurement of soil thermal resistivity. A thorough knowledge of the thermal properties of a soil will enable the user to properly install and load underground cables. The method used is based on the theory that the rate of temperature rise of a line heat source is dependent upon the thermal constants of the medium in which it is placed. The designs for both laboratory and field thermal needles are also described in this guide

The purpose of this guide is to provide sufficient information to enable the user to select useful commercial test equipment, or to manufacture equipment which is not readily available on the market, and to make meaningful resistivity measurements with this equipment. Measurements may be made in the field or in the laboratory on soil samples or both. If the native soil is to be tamped back into the trench at the same density at which it was removed, it may be desirable to make in-situ resistivity measurements along the route of the cable. If the native soil is to be placed in the trench at a density different than undisturbed soil in the same vicinity, laboratory measurements are required on soil samples recompacted to the desired density. In order to draw meaningful comparisons on selected foreign backfill materials, thermal resistivity measurements should be made in the laboratory on soils which are compacted so as to provide maximum dry densities.

New IEEE Standard - Superseded. A method for measurement of soil thermal resistivity that is based on the theory that the rate of temperature rise of a line heat source is dependent upon the thermal constants of the medium in which it is placed is given. This information will enable the user to properly install and load underground cables. The aim is to provide sufficient information to enable the user to select useful commercial test equipment, or to manufacture equipment that is not readily available on the market, and to make meaningful resistivity measurements with this equipment, in the field or on soil samples in the laboratory. Designs for both laboratory and field thermal needles are described.