Sensitivity of Neutron Probe Moisture Measurements to Use in Suboptimal Settings.

The soil neutron probe is the reference standard means of measuring soil moisture content in an undisturbed landscape setting. However expensive aluminum tubing is typically used to support the instrument and vertically guide its emitter/detector to the proper depth. In this work we examine the use of PVC tubing as a replacement.  We also inspect the possibility of using a 1.5” (3.8 cm) diameter neutron probe in tubing gauged for a 2” (5.1 cm) diameter instrument.