Boasting a rich array of sophisticated features and proprietary technology, GMR elevates surface NMR geophysics, delivering superior performance and data quality in an ever-expanding range of environments and applications.



Deep Multi-Channel Surface NMR

  • Designed from the ground up for multi-channel capabilities
  • Highest output power
  • Greatest depth of investigation
  • Shortest dead-time
  • Proven ruggedness worldwide
  • Accurate for deep or shallow imaging

Multi-Channel Hardware that Delivers

Built from the ground up to capture the advantage of multi-channel processing, sophisticated GMR hardware provides unmatched performance and superior results. Cutting-edge electronics exhibiting wideband receive are packaged in a modular design with an emphasis on reliability, safety, and performance. Advantages such as the highest power output, the fastest switching, and the most flexible multi-channel architecture† on the market all translate directly into enhanced imaging capabilities with detection of deeper, shorter, and smaller NMR signals.


540V DC/DC Converter


  • Max bus voltage: 540V DC
  • Charge current: 1A
  • Capacitance: 0.054F
  • Power supply: two 12V batteries


  • Auto-shut down for safety in case of improper connection
  • Analog voltage meters on panel


  • Two DC/DC converters can be used in parallel

4800V Standard Transmitter or 6000V XHV Transmitter


  • Standard output: 4800V, 600A, 25As
  • XHV output: 6000V,800A
  • Ultra-short dead-time: <5ms
  • Four full-duplex Tx/Rx channels
  • Wide band receiver noise <300pV/rt(Hz)
  • Pulse sequences with phase cycling:
    • FID (T2*)
    • 4-Phase&Crush-Recovery(T1)
    • Spin echo & CPMG (T2)
    • Adiabatic sweeps†
  • Compatible with shielded cables and separated transmit/receive loops


  • Auto-shutdown in case of improper connection
  • Environmentally-rated connectors with no-touch contacts


  • Expandable to 8 or 12 channels

16μF Tuning Unit


  • Auto-shutdown in case of improper connection
  • Transmitter operates only when tuning lid is securely closed and shuts down if opened


  • Expansion 16μF tuning unit for up to 32μF capacitance (only suggested for low Earth latitudes)

Four-Channel 4800V Tx/Rx Expansion Module

Adding Four Fully-Functional Tx/Rx Channels

Four-Channel Reference Sensor Module

Adding Four Synchronized Receive Channels

High-Voltage Surface Cables

Environmentally Rated Connectors