Vista Clara advanced NMR soil moisture systems deliver fast, accurate characterization of soil moisture by NMR without any need for sample extraction, porosity calibration, or radioactive sources.  A flexible modular design allows the user to deploy the non-invasive Discus Surface Sensor or in-situ Dart Probe using same powerful electronics and software.

DISCUS and Dart MEASUREMENTS PROVIDE

  • Direct and quantitative determination of soil moisture
  • Classification of bound versus mobile water fractions
  • Estimation of pore size, permeability, and field capacity
  • Freedom from nuclear radioactive sources, sample extraction, and borings

DISCUS and dart APPLICATIONS IN HYDROLOGY INCLUDE

  • Geotechnical investigations and road bed compaction analysis
  • Agricultural optimization of irrigation and drainage
  • Non-destructive testing of concrete and asphalt moisture
  • Scientific studies of soil, permafrost, and carbon cycling

How Discus Works

The Discus system operates like an in-side-out MRI.  Magnets in the flat Discus sensor polarize water molecules in the soil and internal coils excite and measure NMR signals associated with the water molecules.  The signal amplitude directly reflects the quantity of soil moisture and the decay time of the signal reflects the soil texture.  By acquiring measurements at different frequencies, Discus obtains a profile of soil moisture at discrete depth intervals.

How Dart Works

The in-situ Dart probe enables minimally invasive
measurements of soil moisture and texture in the undisturbed formation.  Magnets and coils in the small-diameter sensor excite and measure soil water within a thin cylindrical sensitive shell near the probe tip. The configuration of the Dart is similar to Vista Clara’s Javelin NMR well logging system but is optimized for rapid shallow deployment requirements. Simple augur holes or direct push installed PVC casing now open a window for high-precision and high-resolution soil moisture logging and monitoring.