Development of a Calibration Methodology of the Patient Dose Calibrator

The kerma-area product (PKA) is a useful quantity to establish the reference levels in diagnosis of conventional X ray examinations. A KAP meter can be calibrated in laboratory or in situ, where it is used. The patient dose calibrator (PDC) is a new equipment from Radcal that measures PKA. It was manufactured following the IEC 60580 recommendations. The aim of this study was to calibrate the PDC in order to use it as a standard device for calibration of KAP meters. The materials used were: a radiation system, the PDC, a monitor ionization chamber and an RC6 ionization chamber. The monitor ionization chamber was calibrated against the RC6 secondary standard ionization chamber. After that, the PDC was calibrated using the monitor ionization chamber as reference. The calibration of the PDC in radiation standard beams allows the determination of a special procedure to calibrate the KAP meter. Its behaviour demonstrates low energy dependence and it can be used as a reference instrument to calibrate clinical KAP meters.