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Borehole Geophysical Surveys / +44 (0)1939 210 710

Spectral Gamma Tool

The spectral gamma tool measures the gamma energy spectra, which are produced by the decay of Uranium238, Thorium232, Potassium40, and other man-made radioactive isotopes. Each of these isotopes has a spectral signature that enables its presence to be identified. Standard natural gamma tools provide a total count of natural gamma emissions from these isotopes.

The spectral gamma tool measures the energy of the gamma emissions and counts the number of gamma emissions associated with each energy level.


  • Size:
    1.00m x 60mm
  • Weight:
  • Energy range:
    100keV – 2.8MeV
  • Detector (Nail):
    150mm x 38mm
  • Max. temperature:
  • Max. pressure:

Logging Conditions

  • 2 – 4m/min in normal mode
  • Static in spectral mode
  • Free running

Borehole Conditions

  • Minimum diameter 75mm
  • Air or fluid filled
  • Unlined, or cased
Energy (MeV), measured at a fixed depth