CMD-DUO "Loop Loop" Frequency Domain EM Conductivity Mapper


GF Instruments' CMD-DUO is an affordable “loop-loop” frequency domain EM system suitable for exploration & mapping of minerals, groundwater and other resources, to depths of approx 60m.


  • Geological surveying
  • Groundwater exploration & monitoring
  • Ground contamination mapping & rehabilitation audit
  • Mineral & resource prospecting
  • Investigation of underground pipes/tanks.


• The CMD-DUO uses modern materials & technologies, making it lighter than competitors (Tx = 9.5kg; Rx = 6.2kg). This, combined with longer battery life, is a big advantage over a full days’ work in the field.

• Everything is controlled via Bluetooth from a single, lightweight console (0.7kg); the only cable is a single reference cable joining the two coils (10, 20 & 40m reference cables supplied) – This makes it less prone to snagging, and more user friendly than competitive systems.

• The CMD-DUO is a wide-bandwidth, “single range” instrument, so the user is not required to guess, then select a limited “measurement range”; simply switch on and go.

• Sophisticated noise-rejection technology allows the CMD-DUO to be used in culturally noisy areas (eg close to power lines).

• The instrument is factory calibrated, so there are no calibration procedures before measurement, or periodical adjustments required.



  • Graded depth range (7.5 - 60 m)
  • Manual or continuous measuring modes
  • High temperature stability and noise resistance
  • Smart and rugged design
  • Rechargeable Li-Ion cells (one charge gives 1-2 working days) or AA cells
  • Easy control system with graphical screen and large memory
  • Data download via USB port or flash disk
  • Bluetooth communication with probe



Transmitter and receiver coils are connected with distance/reference cable.


  • Measured quantities:
      Apparent conductivity in mS/m
      In-phase ratio in ppt (informative values)
  • Measuring range: 1000 mS/m, resolution 0.1 mS/m
  • Measurement accuracy: ± 4% at 50 mS/m
  • Full and half depth range (vertical and horizontal orientation of dipoles)
  • Power supply: Li-Ion battery packs (one charge for up to 20 hours of work)
  • Operating temperature: -10 °C to +50 °C
    Effective High/Low Depth Range Dipole Center Distance
    15 / 7.5 m 10 m
    30 / 15 m 20 m
    60 / 30 m 40 m

  • Dimensions / Weight
      Transmitter: 65 cm diameter / 9.5 kg
      Receiver: 65 cm diameter / 6.2 kg
    Complete working weight of the set with 20 m cable is 17.7 kg.


Control Unit:

    Connection with coils is provided by integrated Bluetooth technology.
  • Five modes of measurements:
          - Manual measurement
          - Continuous measurement
          - GPS Manual measurement
          - GPS Continuous measurement
          - Search mode
  • Measuring time: 1 – 20 s
  • Direct support of GPS receiver with UTM/UPS possibility
  • Data flash memory: 128 MB
  • Power supply: Li-Ion battery pack (one charge up to 32 hours of work)
  • Dimensions: 270 x 90 (145) x 60 mm
  • Weight: 0.7 kg 

Download the Brochure - CMD-DUO.pdf  (1.5MB)

Please contact us for pricing

 Ph: +27-(0)11-467-3371

Mobile: 082 89 2 9771