BTG-01 Borehole Gamma Probe

The BTG-01 is a fully digital gamma probe that integrates four different energy windows of gamma rays over a time of 0.5 seconds. The four windows are calibrated to the four windows:

Total Count = 0.10 - 3.00 MeV

Potassium   (K40) = 1.37 - 1.57 MeV

Uranium   (Bi214) = 1.66 - 1.86 MeV

Thorium   (Tl208) = 2.40 - 2.80 MeV

The standard detector used in the gamma probe is a 25mm by 76 mm crystal (1”x 3 “ CsI). Larger sizes are available and are listed under options.

The four-channel gamma probe is designed for use with all standard IFG logging systems that include the BIN-04 digital data interface, 4 conductor logging cable and the data acquisition software. The probe is controlled by an on-board microprocessor that transmits the four channel digital data along the logging cable to the surface console (BIN-04) for the re-formatting and the transfer to a microcomputer. The microcomputer and the acquisition software (DAS) display and record the data in real time. Up to a total of 20 different parameters can be viewed during logging, in either graphic or numeric format. The recording format is in continuos or incremental mode.

Post processing software (PC-LOG) is available to process the recorded data. For this process the probe can be calibrated for window stripping, dead time corrections and to compute the energy concentration in parts per million (ppm).


DETECTOR TYPES Nal crystal, resolution 7.5%
Csl crystal, resolution 9.5%
BGO crystal, resolution 15.5%
DETECTOR SIZES 25 mm x 76mm
                19 mm x 76mm
SAMPLE PERIOD 0.5 second, Software selectable
WINDOW CHANNELS Total Count  = 0.10 - 3.00 MeV
Potassium   (K40) = 1.37 - 1.57 MeV
Uranium   (Bi214) = 1.66 - 1.86 MeV
Thorium   (Tl208) = 2.40 - 2.80 MeV
OTHER Single point resistance
PROBE HOUSING Stainless steel
MAXIMUM DEPTH 2000 meters
CONNECTION 4-pin connector (Gearhardt Owen)
TEMPERATURE RANGE Storage:  -35oC to  +70oC
Operating: 0oC to +70oC
OUTPUT 10mA current loop, 4800 baud
SUPPLY VOLTAGE 24Vdc. @ 0.2 (at probe header)
PROBE DIMENSIONS 40mm diameter x 120 cm long


Larger diameter detectors are available on special order. The larger detector sizes increase the probe diameter to:
38 mm X 76 mm Detector Probe diameter = 52 mm Weight = 4.5 kg
50 mm X 76 mm Detector Probe diameter = 65 mm Weight = 5.6 kg
76 mm X 76 mm Detector Probe diameter = 90 mm Weight = 8.0 kg