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Calibrations in the area of brachytherapy

Types of calibrations offered by PTB
PTB supplies calibrations in the unit "reference air kerma rate" (RAKR) for:

  • 192Ir and 60Co high-dose-rate (HDR) sources;
  • 125I low-dose-rate (LDR) sources;
  • well-type ionization chambers for all three types of sources.

Please see also measurement and calibration capabilities.

If you wish other types of calibrations, do not hesitate to contact us. We can then find out whether we can offer the type of calibration required by you.

Execution of the calibration
The sources are calibrated either at our calibration facility for HDR sources, or with PTB's primary standard for LDR brachytherapy sources. HDR sources are calibrated with a calibrated spherical ionization chamber at a distance of 1 m from the source. The primary standard used for the quantity "reference air kerma rate" (RAKR) for LDR brachytherapy seeds is the extrapolation chamber GROVEX (large-volume extrapolation chamber – for the German term "GROßVolumige EXtrapolationskammer") (Publications). For more background information on the set-ups used, please click here.

Ionization chambers (well-type) are calibrated by means of a calibrated source. We normally keep HDR brachytherapy sources (60Co and 192Ir) at our disposal. For the calibration of ionization chambers with LDR iodine seeds, uncalibrated seeds normally have to be provided by the customer since, given the short half-life of 125I seeds, these cannot be kept available at PTB permanently. Iodine seeds are first calibrated with the LDR primary standard before the actual calibration of the well-type chamber takes place.

How to apply for a calibration
Please send your calibration application in writing (e.g. via e-mail) to one of the above-mentioned contact persons, including the following information (if applicable):

  • type and extent of the calibration (e.g. secondary standard calibration, source calibration, combinations of both);
  • source type (nuclide and manufacturer identification);
  • the measuring instruments you provide;
  • desired deadline, and
  • information concerning the shipping of the source.

Soon after that, you will then receive a quote specifying your contact person, the expected costs and further details concerning the process.

The calibration fees are based on the Regulations Governing Charges for Services Supplied by PTB (KVONL).

From 01.02.2019 the costs are settled by fixed fees. The basis for this is the corresponding amendment to the Regulations Governing Charges for Services Supplied by PTB (KVONL). In the table below, you will find the corresponding fees for the PTB calibrations in the field of brachytherapy. If the actual costs for providing your order deviates significantly from the listed fixed fees, the costs will be calculated on the basis of the actual amount of tome neede.

New fixed prices apply from 01.10.2021 (highlighted in red, plus value‑added tax at the currently valid VAT rate, unless the VAT number is provided).

Calibration taskSource typeFixed fee
(in Euros)
Calibration of an HDR source or LDR seeds in reference air kerma rate (RAKR)192Ir, 60Co, 125I



Calibration of another source in the context of an order



Calibration of a well-type ionization chamber in reference air kerma rate (RAKR)192Ir, 60Co, 125I



Calibration with another source in the context of an order



Table: Standard calibration tasks for brachytherapy provided by PTB and the corresponding fixed fees.


Friedricke Grote
Phone: +49 (0) 531 592 6252
Angelika KasperPhone: +49 (0) 531 592 6242
Dr. Rolf Behrens
Phone: +49 (0) 531 592 6340
Dr. Thorsten Schneider
Phone: +49 (0) 531 592 6346