BGR-01 Gamma And Electrical Property Probe

The BGR-01 combination probe contains the gamma detector and the electrodes for the resistivity measurement. The probe has a 40-mm diameter non- magnetic non- conductive housing, which is pressure, rated to 3,000 meters. The probe is controlled by an on- board microprocessor that samples the potential between the two electrode arrays at a rate of 2 samples per second. The potential range of the measurement is +/-50V and has a resolution of 0.1mV. When switching the current generator "OFF" the BGR-01 probe will measure the spontaneous potential voltages in the borehole.

The signals from the gamma sensor in the probe are integrated in four different energy windows 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 gamma detector used in the probe is a 25mm by 76 mm crystal ( 1”x 3 “ CsI ). Larger sizes are available and are listed under options.
The gamma / resistivity combination 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 all the data along the logging cable to the surface console 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
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
RESISTIVITY RANGE 0 to 50,000 ohm-m
INPUT CURRENT 2,5,10,20mA (selectable)
PROBE HOUSING High strength filawound tube
MAXIMUM DEPTH 3000 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 48Vdc. @ 0.2 (at probe header)
PROBE DIMENSIONS 40mm diameter x 200 cm long