DGA Focused Gamma Tool
DGA
Directional Gamma Tool (1.36” OD)
The DGA Directional Gamma Tool is used for Azimuthal Geosteering and is our standard Tungsten-collimated version of the NGT-T gamma tool. These tools are sometimes referred to as “focused” or “shielded” gamma tools. In this design a 67° “window” is machined along the length of the Tungsten shield that surrounds the crystal/phototube detector. Only gamma ray entering from the formation through this window can be detected and counted. When aligned with the tool face or other physical reference, the DGA indicates the direction from which gamma ray energies originate.
The DGA is interchangeable with the standard NGT-T gamma tool and is the same overall length and diameter.
For higher sensitivity version of DGA, please see DGA-C.
To protect your gamma investment and ensure the best performance use CBG original SNB Snubbers-Shock & Vibration Isolators.
DGA
Directional Gamma Tool (1.36” OD)
The DGA, Directional Gamma Tool, is our standard Tungsten-collimated version of the NGT-T gamma tool. These tools are sometimes referred to as “focused” or “shielded” gamma tools. In this design a 67° “window” is machined along the length of the Tungsten shield that surrounds the crystal/phototube detector. Only gamma ray entering from the formation through this window can be detected and counted. When aligned with the tool face or other physical reference, the DGA indicates the direction from which gamma ray energies originate.
The DGA is interchangeable with the standard NGT-T gamma tool and is the same overall length and diameter.
For higher sensitivity version of DGA, please see DGA-C.
To protect your gamma investment and ensure the best performance use CBG original SNB Snubbers-Shock & Vibration Isolators.
DGA Specifications
P/N 202-000-000
| Detector | Scintillator Crystal | Sodium Iodide, Na(TI) | |
|---|---|---|---|
| Photomultiplier | R3991A (Hamamatsu) | ||
| Mechanical | Diameter (OD) | 1.36” | |
| Length (make-up) | 13.7” | ||
| Weight | 3.0 lb | ||
| End Connectors | Micro-D Subminiature, 15-Pin | ||
| Material | Aluminum Alloy (chassis), Tungsten (shield) | ||
| Performance | Sensitivity | 0.35* CPS/API | |
| Front/Back Count Ratio (using source at 6”) | 7.4 using Barium-133 1.8 using Cesium-137 |
||
| Accuracy | +/- 5% to 300°F +/- 10% to 350°F |
||
| Operating Temperature | 0°F to 350°F | ||
| Survival Temperature | -40°F to 400°F | ||
| Vibration (3 axis) 50-1000Hz, Random | 30G (20G RMS) | ||
| Environmental | Heat/Cool Rate, Max. | 5°F per minute | |
| Shock (3 axis) | 1000G, 0.5ms, half-sine | ||
| Power Requirements | DC Input Voltage | 17-48 VDC, 50VDC Max. | |
| Tool Current | 8-11 mA | ||
| Output Signal | Negative Pulse | +5V to GND, 5 uSec width |
* Counts are collected with gamma tool mounted within standard BeCu pressure barrel, (OD 1.875″, ID 1.500″). API Calibration performed with AEA Technology, QSA Inc., KUTh Field Verifier #188074, S/N 255 Radionuclides: K-40(11.7%), U-238(90 ppm), Th-232(40 ppm).