Ionisation chambers are calibrated directly against the primary standard of air kerma for medium-energy X-rays, the Medium Energy Free Air Chamber (MEFAC).
Radiotherapy ionisation chambers can be calibrated directly in megavoltage photon beams from a medical linear accelerator.
This service is aimed at parallel plate ionisation chambers of the type used to measure electron beams.
The low energy X-ray calibration service is intended for thin-window plane-parallel chambers required for the dosimetry of superficial X-ray beams (typically less than 70 kVp).
We calibrate electrometers which are used for radiotherapy dosimetry.
Calibrations are performed with the ionisation chamber in a water phantom using ARPANSA’s Eldorado teletherapy head.
Guidance on the recommended voltage for each chamber type.
The most common chamber types currently in use in Australia include the 2571 Farmer chamber, the IBA FC65‑G and the PTW 30013.
Information on available for clinics seeking traceable measurements for brachytherapy sources.
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