PTB testing method for finger ring dosemeters has proven its effectiveness
The dosemeters used to measure beta radiation have been subjected to an annual quality control by the PTB for six years now. Since then, all dosimeter models used in Germany have passed these controls.
In Germany, for persons who are occupationally exposed to radiation, monitoring with personal dose equivalent meters is legally prescribed. Besides the whole-body dosimeters which are to be worn on the trunk, also passive extremity dosimeters are used which are often worn around the fingers. Extremity dosimeters are used for beta radiation measurements, especially in medicine. All dosimeters of this type are released and assessed by dosimetry services. PTB is thereby responsible for quality control. Quality control takes place in two stages:
In the first stage, the designs are submitted to a thorough check with regard to their properties before the dosimeter is released for use. In the case of beta dosimeters, this control is carried out according to a directive.
In the second stage, the routine operation is checked yearly at the dosimetry services via so-called “periodic comparison measurements”. The dosimeters are thereby exposed by PTB to a well known dose – which we we will call HPTB in the following. Then, the dosimetry services analyse the dosimeters and determine their measured value, HDST, of course without knowing the value of HPTB. As a measure of quality, the quotient HDST/HPTB is used which is 1.0 for an ideal dosimeter. The figure shows the values of these quotients in relation with the dose for all comparison measurements which have been carried out with beta radiation up to now. The lines plotted indicate the admissible limits for this quotient. Due to the requirements of radiation protection, these limits narrow towards high doses.
The condition for passing the yearly comparison measurements is that 90% of all quotients for each design of a service lie within these limits. If this requirement is not met by one dosimeter design for the comparison measurement, a repetition is carried out for this dosimeter. This has never been the case up to now. In summary, one can say that this type of two-stage quality control is particularly efficient.
Contact:
Dr. Rolf Behrens, PTB Working Group 6.34 Beta Dosimetry, Phone +49531-592 6340, e-mail: rolf.behrens@ptb.de
Media Contact
More Information:
http://www.ptb.deAll latest news from the category: Physics and Astronomy
This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.
innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.
Newest articles
Properties of new materials for microchips
… can now be measured well. Reseachers of Delft University of Technology demonstrated measuring performance properties of ultrathin silicon membranes. Making ever smaller and more powerful chips requires new ultrathin…
Floating solar’s potential
… to support sustainable development by addressing climate, water, and energy goals holistically. A new study published this week in Nature Energy raises the potential for floating solar photovoltaics (FPV)…
Skyrmions move at record speeds
… a step towards the computing of the future. An international research team led by scientists from the CNRS1 has discovered that the magnetic nanobubbles2 known as skyrmions can be…
