OFITE, 11302 Steeplecrest Dr., Houston, TX 77065 USA / Tel: 832-320-7300 / Fax: 713-880-9886 / www.ofite.com
10
The Gamma Ray Logger should be calibrated with spectral standards once
per month, or after the Gamma Ray Logger has been moved. Calibration
can also be done more frequently at the user’s discretion. During a spectral
calibration, the software automatically advances the conveyor belt and scans
each of three standards (Potassium, Uranium, and Thorium) for 10,000
seconds each. The total time for the procedure is about nine hours. We
recommend starting the test at the end of the day so that it can run overnight.
Always store the Gamma Ray Standards in the horizontal position. Do not
stand them up vertically.
The limit switch at the end of the conveyor belt is disabled during
calibrations. It will not stop the motor when a core reaches the end of
the belt. Before starting the calibration, make sure nothing is on the belt
between the shield and the limit switch.
Important Notice Concerning Calibration Standards:
There is no globally
accepted industry standard or calibration methodology for gamma ray
standards for spectral gamma ray loggers. The OFITE Spectral Gamma
Ray standards are manufactured to the following concentrations: 100 ppm
Uranium, 100 ppm Thorium, and 4.5% Potassium. The standards are
manufactured in molecular proportions to achieve these concentrations. In
the event that this calibration standard does not meet desired requirements or
expectations, please contact OFITE.
1.
Place the three standards on the belt with Potassium first, then Uranium,
then Thorium. Place the Potassium standard centered under the shield
and leave 12 inches between the standards.
Shield
Height Sensor
Calibration
Spectral
