Capintec CAPTUS 2000, Owner'S Manual

Page: 58 / 206

CAPINTEC, INC CAPTUS
®
2000
setup information and return to the main autocalibration screen, or CANCEL to exit without
saving and return to the main autocalibration screen. The Constancy Test uses this
calibration information to decay correct the Cs137 rod source.
Select the
CONSTANCY button from the main Autocalibrate screen which is shown in Figure
5-1. Figure 5-6, will appear.
Figure 5-6
Select
OK to begin the Cs137 measurement process, or Cancel to return to the main
autocalibration screen. Since the constancy test is a measure of reproducibility, it is very
important that the source be placed in exactly the same position each time the constancy test
is performed. Place the Cs137 rod source in the well of a drilled well detector with the black
tip down.
For an easy way to insure reproducible source placement for the uptake probe, turn the
uptake probe so that the collimator opening is facing upwards towards the ceiling. Gently
place the black, flat plastic end of the source onto the middle of the surface of the crystal.
NOTE: The source is plastic and can be safely placed against the surface of the detectors
when handled carefully. This placement will provide good positioning for reproducibility and
acceptable count rates for quick calibration of the flat field detector using the reference
source provided with the system.
Once the source is correctly placed, select
OK to begin the Reproducibility Test, or CANCEL
to return to the main autocalibration screen. To stop the counting process, select ABORT
during acquisition. You will return to the main autocalibration screen. When the process is
complete, "DONE" appears in the MCA display area. The system will count until at least
2000 vertical scale peak counts have been acquired. After completion of the constancy test,
the total count rate, live count time, calculated standard activity, measured activity, and
percent error will appear in the display area. The results of each constancy test is
automatically saved to a calibration file. The daily quality assurance tests should only take
about three minutes for each detector.
5-6 QUALITY ASSURANCE July 00