2. According to the provisions of the
Radiological Safety Norms in
Interventional Radiology and
Radiology Practices (NSR-11), the
authorization holder should keep a
record of the radiation field
measurements in the controlled areas
and the adjacent areas of the
Controlled Areas for the Points of
Interest specified in the authorization.
The measurement points are set by
CNCAN in the authorization process.
The frequency of measurements is
usually 3 months in the case of dental
x-ray, mammography and
osteodensitometry being 6 months.
3. Dosimetric monitoring of the work environment includes:
-Monthly dispatch of dosimeters before the 1st day of the
month
-Interpretation of thermoluminescent signal, evaluation
and reporting H * (10). Availability of results: 2 - 5
working days after receipt of the dosimeters worn
through the on-line database - RepDoz
- Issuing dosimetric bulletins
- -Account online to tracking results and viewing history
Advantages of using thermoluminescent dosimeters:
- -Modern Technologi which is very sensible
4.
5. • The modern technology, used in most European
dosimetry laboratories individual. Thermoluminescent
dosimeters are currently used in most EU countries for
individual dosimetry monitoring.
• The detectors are made of tissue-equivalent material:
the thermoluminescent crystals used (Li2B4O7) have
Zefectiv close to human tissue which leads to a significant
improvement in personal equivalent dose ratings.
Detector type: - 2 elements: Li2B4O7: With phosphorus
equivalent tissue; - 2 CaSO4 elements: Tm phosphorus
with great sensitivity Ease of use of dosimeters:
• Thermoluminescent dosimeters represent a unitary
system, composed of 4 thermoluminescent crystals
embedded in a special cassette
• There is no need to exchange the box: at the end of each
month, the exposed person professionally handles the
dosimetre worn and takes over the new dosimeter ready for
wearing.
6.
7. Very low dose values can be determined: minimum detection limit of the system the
thermoluminescent is much lower (by 40 - 70%, depending on the field of use) than
that of the film dosimeter. There is a possibility of very small doses, starting at 0.03
mSv, leads to a reduction in cumulative doses over one year. Increased accuracy of
measured measurements due to energy dependence much more (up to 20% for
thermoluminescent dosimeters, compared to about 2000% for film dosimeters)
8.
9. Different colors are used for consecutive months: Thermoluminescent
dosimeters are sealed in special bags, glued on a label with the name of the
person professionally exposed and the unique identifier of the dosimeter.
Elimination of the risk of contamination of dosimeters: sealing dosimeters leads to
avoidance of contamination with various radioactive substances (in the case of
nuclear medicine laboratories or research laboratories), dust, chemicals, etc.
