biodex ATOMLAB 500, Operation And Service Manual, Page: 184 / 212

Dial Value Settings and Source Containers (Glass Vial, Glass
Syringe, etc.)
The Atomlab Dial Value (DV) settings enable the software to convert ion chamber current into a
displayed activity value for the isotope corresponding to the DV selected. The displayed activity
value is directly proportional to the DV.
The isotope’s “source container” is either a vial or syringe; the composition of which may
influence the accuracy of the activity measurement. The DV supplied in the Atomlab User
Guide (Instruction Manual) or pre-programmed into the isotope dial value
are calibrated for use
with the source material in an un-shielded plastic syringe (nominal 1mm wall) while hanging in
the supplied “source dipper” syringe support. For isotopes contained in sealed long-lived QA
sources (e.g., Cs-137), the DV supplied are calibrated for use with type Vial E epoxy sources or
equivalent. Yttrium-90 is listed in a plastic syringe, a vial, and Sir-Spheres.
Accurate measurement of unsealed sources in any other configuration must be with a new
Container Dial Value (CDV) determined by the user with the following procedure. During the
following steps, set the DV to the Atomlab published value.
Container with No Source Material:
1. Assay a quantity of isotope source material in a plastic syringe with a nominal wall
thickness of 1mm and record as (Plastic Syringe Activity) 1.
2. Transfer part or all of the source material from the plastic syringe into the empty container.
3. Assay the container with the isotope source material and record it as (Container Activity).
4. Assay the partial or empty plastic syringe for residual activity and record it as (Plastic
Syringe Activity) 2.
5. Calculate the CDV for use with the isotope assayed in that type of container:
𝐶𝐷𝑉 =
!" × !"# ! ! !"# !
!"#$%&#'( !"#$%$#&
Where: PSA = Plastic Syringe Activity.
Container with Source Material:
1. Assay the container with the isotope source material and record it as (Container Activity) 1.
2. Transfer part or all of the source material from the container into a plastic syringe with a
nominal wall thickness of 1mm.
3. Assay the plastic syringe with the isotope source material and record it as (Plastic Syringe
Activity).
4. Assay the partial or empty container for residual activity and record it as (Container Activity)
2.
5. Calculate the CDV for use with the isotope assayed:
𝐶𝐷𝑉 =
!" × !"#
!" ! ! !" !
Where: PSA = Plastic Syringe Activity.
CA = Container Activity.