In addition to its primary role as a lithological or clay indicator, a natural gamma measurement is frequently used as the basis for establishing correlations between boreholes and to ensure accurate depth matching between diferent logging runs made in the same borehole. For these reasons, many Electromind probes provide this measurement as an additional log along with other parameters.

The GRT38 probe provides a solution for cases where only a basic, total counts natural gamma log is required and also provides a borehole fluid temperature measurement useful for correcting certain other logs. Based on a ø 25 x 50 mm NaI(Tl) scintillation crystal detector coupled to a high-performance photomultiplier tube, the probe boasts excellent sensitivity (±1.2 cps / API unit) and provides a high quality fnal result.

For clients requiring this additional parameter, the probe can be factory ftted with a casing collar locator (CC)) detector.

Optionally, the probe can be provided with a calibration certifcate allowing the raw counts per second results to be converted to industry- standard API units.

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  • diameter : 38 mm
  • Length : 1 180 mm
  • Weight : 3kg
  • Max. operating temperature: 70°C
  • Max. operating pressure : 200 bar

  • Natural gamma detector: ø25 x 50 mm NaI(Tl) crystal
  • Temperature range : 0 to 65°C
  • resolution : 0.001°C

  • CCL detector
  • Calibration : factory calibration in API units

  • Dry or fluid-flled borehole
  • Open or cased borehole

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