NMR Solutions for Soil and Core

Man-portable NMR Geophysical Instruments for Soil, Sediment and Core Measurements

Vista Clara’s family of man-portable NMR tools enable direct measurement of volumetric water content and high-resolution pore-scale analysis of soils, sediments and core samples. These tools are all man-portable and designed for use in the field.

  • The Discus and Dart tools operate from a common, battery-powered NMR control unit, that can be carried in one hand and operated outdoors in all weather conditions
  • The Dart™ NMR logging tool is the world’s only man-portable, battery-powered NMR logging tool, and packs powerful NMR measurement capabilities in a lightweight, small-diameter form factor
  • The Discus™ sensor provides rapid, non-invasive measurement of near surface soil moisture content, with the ability to profile water content in four separate depth zones ranging from 1 inch to 8 inches (2.5 to 20 cm) 
  • The Helios™ Soil and Core Sample Analyzer enables measurement of a wide range of soil and core samples, with diameters up to 4 inches, and with a unique combination of short echo spacing, wide bandwidth and low static field strength to mitigate the effects of magnetically susceptible rocks and soils 

These man-portable instruments provide direct, low-cost, high-resolution measurements of hydrogeological properties that users really care about, including:

  • Volumetric water content
  • Pore size distribution
  • Bound and mobile porosity
  • Hydraulic conductivity
  • Transmissivity

A single NMR log can provide all of these key hydrogeological properties at vertical resolution on the order of 25 to 50 centimeters (10 to 20 inches), enabling unambiguous and precise characterization of the water storage and pore structure characteristics of any earth formations.


Portable Go-Anywhere Magnetic Resonance Logging Solution

Dart packs the power of magnetic resonance logging into a highly portable, battery-powered system operable by a single user. With Dart, any small-diameter bore—no matter how remote—becomes an opportunity for a high-resolution hydrogeologic log.

Dart is the world’s first and only hand-portable NMR logging tool, enabling single-person manual deployment to remote or environmentally sensitive locations, and eliminating the need for a multi-person crew or vehicle. Dart runs on batteries that last up to a full day of logging. A single user can transport and operate a Dart system, even in rough or challenging terrain.

Discus/Dart NMR Control Unit:

The Discus and Dart sensors both operate from the Discus/Dart NMR control unit. This rugged and highly portable product functions as a complete, field capable NMR spectrometer. The Discus/Dart control unit provides power, wideband RF power amplification, NMR pulse sequence generation and synchronous low-noise NMR signal data acquisition, all in one environmentally-sealed enclosure. This unit interfaces with a Windows field tablet or laptop via a single USB connection, enabling NMR measurements to be acquired and analyzed in real time in the field.

Dart NMR Logging Probe:

The Dart NMR logging probe features high performance NMR measurement capabilities, making it ideal for measuring water content in near surface soils and sediments:

  • A very short echo spacing (< 500 us) for the most accurate measurement of water content in unsaturated soils and sediments,
  • High vertical resolution (~9 inches/23 cm) for high resolution site characterization
  • Simultaneous measurement in two separate cylindrical sensitive zones with diameters of 5 inches (12.5 cm) and 6 inches (15 cm). These sensitive zone diameters are ideal for logging small diameter core holes, auger holes, or 2 inch (50mm) PVC-cased wells installed by direct push or small diameter sonic drilling
  • Dart operates at frequencies between 420 kHz and 480 kHz, avoiding large radio frequency interference in the worldwide AM broadcast band (530 – 1610 kHz)

Dart Applications:

  • Environmental Site Characterization
  • Environmental Monitoring
  • Mining
  • Geotechnical
  • Shallow Groundwater Resources

A number of the features included in Dart are patented as follows:: US 10,302,733, 10,113,982 B2; US 10,162,026 B2; US 10,302,733 B2; US 9,348,054 B2; US 9,588,068 B2US 8,816,684 B2; US 8,736,264 B2
* Available with advanced diffusion measurement software for characterization of hydrocarbon contaminants

For More Info:
Download Dart Specifications Sheet


Non-invasive, non-radioactive-source soil moisture measurement

Discus delivers fast, accurate, and non-invasive measurements of soil moisture and texture from the surface, removing the need for sample extraction, calibration, or radioactive sources. Discus provides determination of soil moisture (water content) at four discrete depth intervals, ranging from 1 inch to 8 inches (2.5 to 20 cm). The NMR relaxation time distribution also indicates the pore size distribution and soil characteristics.

Key capabilities of Discus include:

  • Direct quantification of soil moisture
  • Completely non-invasive investigations
  • No radioactive sources or licensing
  • No soil-specific calibration for moisture content
  • Fast measurement time (3-10 minutes)
  • Measurement results available immediately in the field
  • Bound versus mobile water classification
  • Estimation of permeability & pore size
  • Ability to non-invasively measure soil water content beneath asphalt and stonework

A number of the features included in Discus are patented as follows:: US 10,302,733, US 8,816,684 B2

For More Info:
Download Discus Specifications Sheet


Field portable NMR analyzer optimized for soils and core samples

Helios NMR measurements enable rapid quantification of fluid content and hydrogeologic properties including the total porosity, bound/mobile fluid fractions, pore size distribution, and permeability. Helios’ unique design features allow robust measurements of hydrologic properties over a wide range of core size and lithology.

Helios key capabilities include:

  • Laboratory precision in a field portable, lightweight rugged design
  • Handles soil and rock cores in a wide variety of shapes and sizes
  • Low-field, high-bandwidth operation enables accurate measurement of water content in magnetically susceptible rocks and sediments
  • Short echo spacing (~200 us) enables high SNR and high accuracy measurement of water in clays and unsaturated samples

Helios Applications:

  • Water resources
    • Determination of bound/mobile water fractions
    • Estimation of hydraulic conductivity
    • Development of NMR logging permeability models
  • Mining – moisture content in ore cuttings and core samples
  • Environmental remediation – detailed analysis of water-bearing properties of core samples
  • Geotechnical

Features included in Helios are patented as follows:: US 10,302,733

For More Info:
Download Helios Specifications Sheet

For a list of other resources: visit our Reference Library