Inter-laboratory comparisons

Inter-laboratory comparisons are undertaken to verify that a laboratory provides correct results within the stated measurement uncertainty. The IAEA offers this service to members of the IAEA/WHO Network of Secondary Standards Dosimetry Laboratories.

An independently monitored dosimetry verification is necessary for Secondary Standards Dosimetry Laboratories (SSDLs) to demonstrate their ability to properly maintain the radiation measurement capabilities, and to determine the level of agreement between their national dosimetry standards and the reference international standards. The IAEA’s Dosimetry Laboratory is the central laboratory of the IAEA/WHO SSDL Network and provides the link between the member laboratories and the international measurement system.

The Agency offers the SSDL Network members a service of inter-laboratory comparisons so that participating laboratories can compare their dosimetry calibrations with those of the IAEA. Comparisons are organized in the field of radiation protection, radiation therapy (external beam radiotherapy only) and diagnostic radiology.

For the comparison, the IAEA sends a calibrated ionization chamber to the participating laboratory for calibration. The calibration results of a participant laboratory and the IAEA are compared relative to the stated measurement uncertainties. If a discrepancy is identified it is resolved together with the Laboratory involved.

The IAEA’s Dosimetry Laboratory also participates in inter-laboratory comparisons organized by regional metrology organizations across the globe. The objective of these comparisons is to verify and support the calibration and measurement capabilities of the IAEA Laboratory.