Georadis GT-40
Geophysical/Environmental Gamma-Ray Analysizer

The RT-40 represents a major advance in portable gamma-ray spectrometers, offering many new features for geophysical and environmental applications.

The compact, one hand unit with integrated GPS gives user very pleasant field operation. The high sensitivity detectors combined with sophisticated mathematical method provides accurate and reliable results at real time.

The GT-40 and GT-40-S are identical except type of detector. The GT-40 has 3x3” NaI(Tl) detector and with high sensitivity and good resolution can be used at most field application. The GT-40-S has 2x2” BGO detector with lead shielding and should be used for focused measurement of cores or at stratigraphy measurements.

The GT-40 utilise advanced DSP, 1024 channel linear energy spectrometer and pile-up rejector with build in continuous analysis. It also uses an advanced method of automatic stabilization on natural background radiation throughout its operation. This unique stabilization method eliminates the need for an additional radioactive check source.

The GT-40 has user friendly navigation joystick and sun readable colour display. Brightness is automatically controlled according external lightning.


Using internal calibration constants, the GT-40 can compute concentration in %K, ppm of U and Th. Results are displayed immediately after end of measurements. They can be stored in the instrument and/or sent to appropriate external device via Bluetooth or Wi-Fi. High sensitive integrating GPS receiver can automatically record the position and store it with each measurement. Measurements can be stamped also by voice notes. Stored voice messages can be replicated by built in speaker.

The GT-40 is powered by a high energy rechargeable lithium pack with built-in charger. This permits operation with the true time measurement up to 15 hours.

The versatile GeoView software package provides all necessary data download to PC, calendar based survey result, spectrum view, data presentation and export survey to e.g. Google Earth.

  • GT-40 Product Photo
  • GT-40 Product Photo
  • GT-40 Product Photo
  • Mineral Exploration
  • Oil and Gas Exploration
  • Geological Survey
  • Geophysical Mapping
  • K, U, Th and Cs‐137 Assay
  • Uranium Prospecting
  • Core Logging
  • Environmental Monitoring
  • High Sensitivity using 3”x3” NaI(Tl) or 2”x 2” Shielded BGO Detector
  • Advanced DSP Spectrometer
  • Automatic Stabilization on Natural Background
  • Large Sun Readable Colour Display
  • User Intuitive Navigation Joystick
  • Wireless communication via Wi-Fi or Bluetooth
  • Real Time Result stamped by Integrated GPS and Voice Recorder
  • All in rugged One Hand Unit

The GT-40 series is provided with a NaI/Tl scintillator with a3" base diameter and 3" height. A GT-40S model is also manufactured, which is fitted with either an NaI/Tl or BGO detector with a 2" base diameter and 2" height at the customer’s request. The GT-40 model has a built-in 1 cm thick Pb collimator. The collimator is easily removable.


Two basic working modes: Survey, for terrain scanning, and Assay, for determining concentrations of precalibrated radionuclides, i.e. components. Energy calibration of the analyzer is carried out continuously throughout the operating time, and only natural background sources are used for the set-up. Monitoring and analysis results are displayed on a colour graphic display in a well-arranged manner. All acquired data is stored in the unit's memory and can be exported to other devices via USB, Wi-Fi or Bluetooth. Field observations can be recorded and stored along with each measurement using a built-in voice recorder.

Manufacturer’s Product Brochure

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