Diagnostic and Radiotherapy Dosemeter Calibrations
Australian Radiation Services Pty. Ltd. (ARS) together with the National Radiation Laboratory (NRL) in New Zealand provides a successful and competitively priced calibration service for diagnostic and radiotherapy dosemeters.
Diagnostic Dosemeter CalibrationsNRL maintains an X-ray exposure facility with Secondary Standards of radiation exposure. They offer a calibration service for diagnostic dosemeters with calibrations traceable to the Australian National Standards of radiation exposure held by ARPANSA.
X-ray beams are available for calibrating dosemeters for general radiography and fluoroscopy, CT pencil chambers, patient scatter levels, mammography, dentistry, X-ray tube leakage and measurement of AEC input doses and dose rates.
Calibration of non-invasive kVp meters
NRL maintains X-ray plants that are representative of the X-ray plants used for general radiography, fluoroscopy, and mammography. These X-ray plants are used to offer a calibration service for non-invasive kVp meters. The calibrations offered cover the following uses:
Radiography: 50 kVp – 150 kVp
Fluoroscopy: 70 kVp – 110 kVp
Mammography: 25 kVp – 31 kVp
There are economies if a combination of calibrations is required.
Radiographic and fluoroscopic calibrations are performed using a medium frequency constant potential x-ray generator and a tungsten anode x-ray tube with 3.0 mm Al total filtration. Mammographic calibrations are performed using a high frequency X-ray generator and a molybdenum anode X-ray tube with 30 µm molybdenum filtration.
Calibration of the kVp settings on the X-ray plants has been performed in terms of peak spectrum energy using high purity germanium detector spectrometry, and is traceable to fundamental physical constants in the form of known radionuclide gamma ray emission energies.
Radiotherapy Dosemeter Calibration
Calibrations of therapy dosemeters for superficial and orthovoltage therapy and megavoltage therapy are available.
Calibrations of therapy dosemeters are provided for low and medium energy X-rays for a subset of the therapy beams maintained by ARPANSA. For superficial and orthovoltage therapy dosemeters, calibrations are performed free in air against the NRL Secondary Standard with traceability to the Australian National Standards for low and medium energy X-rays.
Calibrations of dosemeters for megavoltage therapy dosimetry are provided as follows:
For NE2571 (or equivalent) chambers:
- Calibration in terms of the absorbed dose to air chamber factor (ND as defined in the IAEA dosimetry protocol TRS277 or ND,air as defined in TRS381). These calibrations are performed in a phantom against the NRL Secondary Standard with traceability to the Australian National Standard for 60Co gamma rays.
- Calibration in terms of the absorbed dose to water calibration factor, ND,w. These calibrations are performed using 60Co gamma rays in a water phantom against the NRL Secondary Standard with traceability to the Australian National Standard for Absorbed Dose.
For any chamber type:
Calibration in terms of exposure, NX, or air kerma, NK, performed in air directly against the NRL Secondary Standard with traceability to the Australian National Standard for 60Co gamma rays. This calibration is performed if the chamber does not fit in the phantom mentioned above.
For more information or to request a quote, please contact us.