biodex ATOMLAB 500, Operation And Service Manual, Page: 76 / 212

Cs-137, 200 µCi, is strongly recommended because the 30-year half-life will ensure use of the
same source throughout the life of the calibrator and the Cs-137 source is readily available. The
Cs-137 source should be replaced at 100 µCi.
Figure 6.2. The Daily Constancy Test Screen
To Perform A Daily Constancy Test:
1. From the QA Dose Calibrator screen touch < Constancy Test>. The Constancy Test screen is
now displayed. The source information is shown.
2. To change sources, touch <Select Sealed Source>. The Sealed Source List screen is
displayed. Locate the desired source by using the <
▲
> and <
▼
> arrows to scroll through
the list. Touch anywhere on the line containing the name of the desired sealed source
and touch <Accept>.
Figure 6.3. Sealed Source List Screen
NOTE: The user can select a default sealed source to be the first source displayed when
entering the Constancy screen. Set the default in Sealed Source Set Up. Otherwise, the
first source displayed will be the first source on the Sealed Source List.
3. If the current background activity reading is higher than desired, touch <Zero
Background> and zero the background.