Neutron probe calibration for the Area 5 vadose zone monitoring system at the Nevada Test Site

The neutron moisture meter (probe) is used to measure in situ volumetric soil moisture levels in a nondestructive, repeatable manner. The purpose of neutron logging in waste pits is to measure moisture levels in the soil profile and changes in soil moisture content above and below buried waste packages. In order to obtain accurate moisture values, the neutron probe must be calibrated for specific site conditions. In this report, soil type, access tube material and diameter, and counting time were site specific factors of concern. 6 refs., 6 figs., 1 tab.