Generalised calibration for the nuclear moisture/density gauge

The application of nuclear moisture/density depth gauges to soil deposits has generally relied on calibration by direct correlation with measured values of moisture content and density. In very soft variable deposits such as coal tailings, direct calibration is not possible. A generalized calibration can be developed from first principles based on the elemental composition of the soil being tested and the application of existing theories. Density and moisture content calibrations are considered separately for two different access tubes, and reasonably reliable calibrations are obtained. In applying these calibrations, an iterative procedure is required since the moisture content has a direct bearing on the elemental composition of the moist soil. The paper gives an insight into the operation and important features of a nuclear gaug