Dosimetry and Medical Radiation Physics
Comparison of Therapy Level Ionization Chamber Calibration Coefficients
An independently monitored dosimetry verification programme is necessary
for the SSDLs to demonstrate their ability for properly maintaining their
radiation measurement standards, and to determine the level of agreement
between their standards and those of the IAEA. For the SSDL network members,
the Dosimetry and Medical Radiation Physics Section of the IAEA conducts
these audits using their radiation measurement standards as the basis of
the intercomparison. The accuracy routinely available with transfer ionization
chambers is sufficient to form the basis of this verification programme.
In this programme, an SSDL calibrates its ionization chamber, then sends
it along with a data sheet to
the IAEA for calibration, and repeats the calibration after the chamber
has been returned. The second calibration at the SSDL would confirm the
safe transport of the equipment. Click
here to download the IAEA-SSDL comparison procedure, using ionization
chamber calibration coefficients.
If a discrepancy is identified in the intercomparison, it is of extreme
importance that the SSDL and the IAEA collaborate to resolve the discrepancy
by direct contact (telephone, e-mail, fax, etc.). The results are kept confidential
and are not distributed without the permission of the participating SSDL.
Interested SSDLs are invited to send a request to the Dosimetry
and Medical Radiation Physics Section of the IAEA for practical arrangements
and scheduling related to their participation in this programme.
A comparison certificate is provided by the IAEA for each successful comparison.
As a general rule, SSDL members are expected to bear the freight and insurance
costs of their ionization chamber from their location to the IAEA in Vienna.
The IAEA will pay for the return costs of the ionization chamber.