Improved laboratory calibration of a single-probe surface gamma-neutron gauge

Surface gamma-neutron gauges are extensively used for the determination of soil physical properties such as density. Substantial differences are sometimes observed between density values provided by these gauges when using factory-supplied calibrations and gravimetric density measurements. These differences can be as high as 16%. In this paper it is shown that, using homogeneous materials with different known densities covering a wider range, it is possible to find a better calibration equation. This calibration provides density values in agreement with gravimetric measurements.