The QL40-SGR probe measures the amount of gamma radiation occurring naturally within the formations crossed by a borehole and counts the number of gamma emissions associated with each energy level. Gamma rays are produced mainly by isotopes of potassium, thorium, and uranium and their decay products. The spectral gamma ray log is widely used in the mining and environmental industries for the identification of lithology, correlation between boreholes, and clay content analyses.

This tool is stackable within the Quick Link (QL) product line or it can be run as a standalone tool. The QL40-SGR operates on any standard wireline (single, 4 or 7 conductor, coax) and in any borehole environment.


  • Mineral Detection
  • Sedimentology- Facies changes and depositional environment
  • Lithology Studies
  • Identify and Classify Clay Types
  • Recognition of Radioactive material
  • Contamination Research

Operating Conditions

Borehole Fluid
[X] Water
[X] Mud
[X] Dry

[X] Uncased
[X] PVC Borehole
[X] Steel

[_] Required
[X] Non-Necessary

Features & Benefits

  • Cutting edge Full Spectrum Analysis (FSA) of data in WellCAD and LoggerSuite
  • Versatile, ubiquitous probe which functions with a wide range of applications and borehole conditions.
  • WellCAD Spectral processing is fast and easy with Medusa calibration
  • Mount Sopris manufactures more natural gamma and spectral tools than any other slim tool manufacturer in the world today.

Specifications – Metric/English

Specification Metric Imperial
Diameter 40 mm 1.6″
Length 0.93 m 36.6″
Weight 6 Kg 13 lbs
Max. Temp. 70ºC 158ºF
Max. Pressure 200 bar 2900 psi


Sensor: Scintillation NaI(Tl) Crystal 2.22- cm x 10.16 cm (0.875 x 4.0”)
Sensor: BGO Crystal- 2.22 cm x 10.16 cm  (0.875 x 4.0”)
Measurement Range: Up to 3000 keV

QL Stack Possibilities

  • QL40SGR + QL40MGS (Magnetic Susceptibility): Mining, Exploration
  • QL40SGR + QL40OBI (Optical Televiewer): Exploration, Bedding Planes, and Fractures in Dry holes
  • QL40SGR + QL40ABI (Acoustic Televiewer): Exploration, Bedding Planes, and Fractures in Fluid-filled holes
  • QL40SGR + QL40ELOG (Resistivity) + QL40FTC (Fluid Res, Temp): Hydrogeologist’s  or Environmentalist’s Tool, Groundwater exploration and assessment
  • QL40SGR + QL40DEV (Deviation): Lithology, Borehole location

Full Spectrum Analysis (FSA)

For more information on this new approach to spectral data analysis, please read our Press Release.


Data Sheet
Please Contact Us for the User Guide

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