GR38: Natural Gamma Radioactivity

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 different logging runs made in the same borehole. For these reasons, many LIM probes provide this measurement as an additional log along with other parameters.

The GR38 probe provides a solution for cases where only a basic, total counts natural gamma log is required.

Based on a ø25 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 final result.

Contact us to get a quote or request more information.



 Simple but efficient

Technical Specifications

Diameter : 38 mm

Length : 1200 mm

Weight : 3.0 Kg

Max. Temp : 70°C

Max. Pressure : 200 bar

Sensors Parameters

 Detector size : ø25 x 50 mm

Options And Accessories

 Calibration : factory calibration in API units

Borehole Conditions

Dry or fluid-filled borehole

Open or cased borehole


Lim designs, produces and commercializes measuring instruments and solutions dedicated to drilling.



  • Blanc Facebook Icône
  • Blanc LinkedIn Icône
  • Blanc Icône YouTube