SIST EN ISO 28057:2018
(Main)Dosimetry with solid thermoluminescence detectors for photon and electron radiations in radiotherapy (ISO 28057:2014)
Dosimetry with solid thermoluminescence detectors for photon and electron radiations in radiotherapy (ISO 28057:2014)
ISO 28057:2014 describes rules for the procedures, applications, and systems of thermoluminescence dosimetry (TLD) for dose measurements according to the probe method. It is particularly applicable to solid "TL detectors", i.e. rods, chips, and microcubes, made from LiF:Mg,Ti or LiF:Mg,Cu,P in crystalline or polycrystalline form. The probe method encompasses the arrangement, particularly in a water phantom or in a tissue-equivalent phantom, of single TL detectors or of "TL probes", i.e. sets of TL detectors arranged in thin-walled polymethyl methacrylate (PMMA) casings.
The purpose of these rules is to guarantee the reliability and the accuracy indispensable in clinical dosimetry when applied on or in the patient or phantom. ISO 28057:2014 applies to dosimetry in teletherapy with both photon radiation from 20 keV to 50 MeV and electron radiation from 4 MeV to 25 MeV, as well as in brachytherapy with photon-emitting radionuclides. These applications are complementary to the use of ionization chambers.
Dosimetrie mit Festkörper - Thermolumineszenzdetektoren für Photonen- und Elektronenstrahlung in der Strahlentherapie (ISO 28057:2014)
In der vorliegenden Internationalen Norm werden Regeln für die Verfahren, Anwendungen und Messsysteme der Thermolumineszenzdosimetrie (TL-Dosimetrie, TLD) für Dosismessungen nach der Sondenmethode festgelegt. Sie ist anzuwenden insbesondere für Thermolumineszenz-Detektoren fester Form und Größe, d. h. Stäbchen, Scheibchen und Mikrowürfel, hergestellt aus LiF:Mg,Ti oder LiF:Mg,Cu,P in kristalliner oder polykristalliner Form. Sieist nicht anzuwenden für LiF in Pulverform; dessen Gebrauch erfordert spezielle Verfahren. Die Sondenmethode beruht darauf, dass einzelne TL-Detektoren oder TL-Sonden, d.h. Sätzen von TL-Detektoren, in ein Wasserphantom oder ein wasseräquivalentes Phantom eingebracht werden. Als TL-Sonde bezeichnet man die Anordnung eines oder mehrerer TL-Detektoren in einem dünnwandigen Polymethylmethacrylat (PMMA)-Gehäuse.
Das Ziel dieser Regeln ist es, die Zuverlässigkeit und Genauigkeit zu gewährleisten, die in der klinischen Dosimetrie bei der Anwendung am oder im Patienten oder Phantom unabdingbar sind. Diese Internationale Norm ist anzuwenden für die Dosimetrie in der Teletherapie mit Photonenstrahlung von 20 keV bis 50 MeV und mit Elektronenstrahlung von 4 MeV bis 25 MeV sowie in der Brachytherapie mit Photonen emittierenden Radionukliden. Die TL-Dosimetrie stellt eine wichtige Ergänzung zur Dosimetrie mit Ionisationskammern dar.
Dosimétrie avec détecteurs de thermolumiscence solides pour le photon et rayonnements d'électron en radiothérapie (ISO 28057:2014)
L'ISO 28057:2014 décrit les règles pour les procédures, applications et systèmes de dosimétrie par thermoluminescence (TLD) pour les mesurages de doses conformément à la technique de la sonde. Elle s'applique en particulier aux «détecteurs TL» solides, à savoir les bâtonnets, les pastilles et les microcubes fabriqués à partir de LiF:Mg,Ti ou de LiF:Mg,Cu,P sous forme cristalline ou polycristalline. Elle ne s'applique pas aux poudres de LiF, étant donné que leur utilisation requiert des procédures spéciales. La technique de la sonde comprend la disposition, en particulier dans un fantôme d'eau ou dans un fantôme équivalant à un tissu, de détecteurs TL uniques ou de «sondes TL», c'est-à-dire des ensembles de détecteurs TL disposés dans des boîtiers de poly(méthacrylate de méthyle) (PMMA) à paroi fine.
Dozimetrija s trdnimi termoluminiscenčnimi zaznavali pri fotonskih in elektronskih sevanjih v radioterapiji (ISO 28057:2014)
ISO 28057:2014 opisuje pravila za postopke, načine uporabe in sisteme termoluminiscenčne dozimetrije (TLD) za merjenje odmerkov glede na metodo s sondo. Uporablja se zlasti za trdna »zaznavala TL«, tj. palice, čipe in mikrokocke iz LiF: Mg, Ti ali LiF: Mg, Cu, P v kristalni ali polikristalni obliki. Metoda s sondo zajema razporeditev (zlasti v vodnem ali tkivu enakovrednem fantomu) enojnih zaznaval TL ali »sond TL«, tj. sklopov zaznaval TL, ki so razporejeni v ohišja iz polimetilmetakrilata (PMMA) s tanko steno.
Namen teh pravil je zagotavljanje nepogrešljive zanesljivosti in natančnosti v klinični dozimetriji pri uporabi pri/v bolniku/fantomu. ISO 28057:2014 se uporablja za dozimetrijo pri teleterapiji s fotonskim sevanjem od 20 keV do 50 MeV in elektronskim sevanjem od 4 MeV do 25 MeV ter pri brahiterapiji z radionuklidi, ki oddajajo fotone. Ti načini uporabe dopolnjujejo uporabo ionizacijskih komor.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 28057:2018
01-december-2018
'R]LPHWULMDVWUGQLPLWHUPROXPLQLVFHQþQLPL]D]QDYDOLSULIRWRQVNLKLQHOHNWURQVNLK
VHYDQMLKYUDGLRWHUDSLML ,62
Dosimetry with solid thermoluminescence detectors for photon and electron radiations in
radiotherapy (ISO 28057:2014)
Dosimétrie avec détecteurs de thermolumiscence solides pour le photon et
rayonnements d'électron en radiothérapie (ISO 28057:2014)
Ta slovenski standard je istoveten z: EN ISO 28057:2018
ICS:
13.280 Varstvo pred sevanjem Radiation protection
SIST EN ISO 28057:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN ISO 28057:2018
---------------------- Page: 2 ----------------------
SIST EN ISO 28057:2018
EN ISO 28057
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2018
EUROPÄISCHE NORM
ICS 13.280
English Version
Dosimetry with solid thermoluminescence detectors for
photon and electron radiations in radiotherapy (ISO
28057:2014)
Dosimétrie avec détecteurs de thermolumiscence
solides pour le photon et rayonnements d'électron en
radiothérapie (ISO 28057:2014)
This European Standard was approved by CEN on 15 August 2016.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 28057:2018 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 28057:2018
EN ISO 28057:2018 (E)
Contents Page
European foreword . 3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 28057:2018
EN ISO 28057:2018 (E)
European foreword
The text of ISO 28057:2014 has been prepared by Technical Committee ISO/TC 85 "Nuclear energy,
nuclear technologies, and radiological protection” of the International Organization for Standardization
(ISO) and has been taken over as EN ISO 28057:2018 by Technical Committee CEN/TC 430 “Nuclear
energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2019, and conflicting national standards shall
be withdrawn at the latest by March 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 28057:2014 has been approved by CEN as EN ISO 28057:2018 without any modification.
3
---------------------- Page: 5 ----------------------
SIST EN ISO 28057:2018
---------------------- Page: 6 ----------------------
SIST EN ISO 28057:2018
INTERNATIONAL ISO
STANDARD 28057
First edition
2014-03-01
Dosimetry with solid
thermoluminescence detectors for
photon and electron radiations in
radiotherapy
Dosimétrie avec détecteurs de thermolumiscence solides pour le
photon et rayonnements d’électron en radiothérapie
Reference number
ISO 28057:2014(E)
©
ISO 2014
---------------------- Page: 7 ----------------------
SIST EN ISO 28057:2018
ISO 28057:2014(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2014 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 28057:2018
ISO 28057:2014(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Rules for the TLD measurement procedure . 9
4.1 Principle of measurement . 9
4.2 Measured quantity . 9
4.3 Measurement cycle .10
4.4 Measurement of the absorbed dose to water .12
4.5 Uncertainty of measurement of the absorbed dose .22
4.6 Reusability .22
4.7 Stability check .23
4.8 Staff .23
5 Requirements for the TLD system .23
5.1 General information .23
5.2 Completeness of the TLD system .23
5.3 Requirements for TL detectors .26
5.4 Requirements for TL-indicating instruments .27
5.5 Requirements for auxiliary instruments (pre-irradiation annealing device) .32
5.6 Requirements for the entire TLD system .32
5.7 Requirements for the calibration irradiation device.35
5.8 Requirements for the accompanying papers .35
5.9 Acceptance tests .35
Bibliography .37
© ISO 2014 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 28057:2018
ISO 28057:2014(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
The committee responsible for this document is ISO/TC 85, Nuclear energy, nuclear technologies, and
radiological protection, Subcommittee SC 2, Radiological protection.
For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO’s adherence to the WTO principles in the Technical Barriers to Trade
(TBT) see the following URL: http://www.iso.org/iso/home/standards_development/resources-for-
technical-work/foreword.htm
iv © ISO 2014 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 28057:2018
ISO 28057:2014(E)
Introduction
The thermoluminescence dosimetry (TLD) with lithium fluoride (LiF) detectors has several advantages,
in particular:
— small volumes of the detectors;
— applicability to continuous and pulsed radiation;
— fair water equivalency of the detector material;
— few correction factors needed for absorbed dose determinations.
The main disadvantage of thermoluminescence (TL) detectors is, however, that they have to be
regenerated by a pre-irradiation annealing procedure. Unfortunately, it is not possible to restore the
former response of the detectors perfectly by this annealing. Provided, however, that all detectors of
a production batch always undergo the same thermal treatment, one can at least determine the mean
alteration of the response of these detectors, with sufficiently small fluctuations of the individual values.
From this mean alteration, a correction factor can be derived.
The essential aim of this International Standard is to specify the procedures and to carry out corrections
[17]
which allow one to achieve (1) a repeatability of the indicated value within a fraction of a percent
and thus, (2) a total uncertainty of measurement (including the calibration steps tracing to the primary
[18][31][25][61][62]
standards) of a few percent, as in ionization chamber dosimetry.
The specifications in this International Standard comprise special terms used in TLD, rules for the
measurement technique, and requirements for the measurement system. The defined requirements and
the testing techniques can, in whole or in part, serve as a basis for stability checks and acceptance tests.
The TLD procedures described in this International Standard can be used for photon radiation within the
energy range from 20 keV to 50 MeV, including photon brachytherapy, and for electron radiation within
the energy range from 4 MeV to 25 MeV, excluding beta radiation brachytherapy. In order to achieve the
repeatability and total uncertainty stated above, this International Standard is applicable in the dose
range above 1 mGy. The upper limit of the minimum measuring range is in the order of magnitude of
10 Gy to 100 Gy. In clinical dosimetry, TL detectors are applied taking into account the requirements of
high spatial resolution, i.e. in the study of the dose distributions with high gradients occurring in small
stereotactic radiation fields and around brachytherapy sources. The other common application is the
measurement of dose distributions in large absorbers, e.g. geometrical or tissue equivalent phantoms,
either within the radiation field or in its periphery. A further usage is the quality assurance of clinical
[1][2][10][12][20][22][26][27][55]
dosimetry by postal dose intercomparison.
The role of this International Standard is not to anticipate national or international codes of practice
in clinical dosimetry, neither for external beam therapy, brachytherapy, whole-body irradiation,
mammography, nor dose measurements outside the treatment field or radiation protection of the staff.
The authors of this International Standard are well aware of the wide spectrum of the methods of
clinical dosimetry, in which TL dosimetry is merely occupying a small sector. But within this framework,
this International Standard provides reliable concepts and rules for good practice for the application
of TLD methods. The items covered include the terms and definitions, the rules for TLD measurement
procedures, and the requirements for the TLD system; this International Standard also addresses
medical physicists and instrument producers. Notably, the numerical examples given are valid for the
TL detector materials and products stated in the publications referred to, and tests may be necessary
to check whether they apply to TLD materials of other producers. The practical examples given, e.g. for
the TL probe calibration conditions and for the numerical values of correction factor, k , accounting for
Q
the dependence of the detector response on radiation quality, Q, are not conceived to be preemptive in
relation to more general standards of the methods of clinical dosimetry or of dose intercomparisons.
Rather, this International Standard provides access to the reliable application of TLD methods based
upon the published results of worldwide development. The long-standing experience in the clinical
[6][13][25][28][29]
usage of TLD, expressed in a set of valuable textbooks, protocols, and recommendations,
[42][43][61][62][54]
has been accounted for.
© ISO 2014 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 28057:2018
---------------------- Page: 12 ----------------------
SIST EN ISO 28057:2018
INTERNATIONAL STANDARD ISO 28057:2014(E)
Dosimetry with solid thermoluminescence detectors for
photon and electron radiations in radiotherapy
1 Scope
This International Standard describes rules for the procedures, applications, and systems of
thermoluminescence dosimetry (TLD) for dose measurements according to the probe method. It is
particularly applicable to solid “TL detectors”, i.e. rods, chips, and microcubes, made from LiF:Mg,Ti
or LiF:Mg,Cu,P in crystalline or polycrystalline form. It is not applicable to LiF powders because their
use requires special procedures. The probe method encompasses the arrangement, particularly in a
water phantom or in a tissue-equivalent phantom, of single TL detectors or of “TL probes”, i.e. sets of TL
detectors arranged in thin-walled polymethyl methacrylate (PMMA) casings.
The purpose of these rules is to guarantee the reliability and the accuracy indispensable in clinical
dosimetry when applied on or in the patient or phantom. This International Standard applies to
dosimetry in teletherapy with both photon radiation from 20 keV to 50 MeV and electron radiation from
4 MeV to 25 MeV, as well as in brachytherapy with photon-emitting radionuclides. These applications
are complementary to the use of ionization chambers.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ICRU 60, Fundamental Quantities and Units for Ionizing Radiation (1998)
ICRU 62, Prescribing, recording and reporting photon beam therapy. International Commission on Radiation
Units and Measurements (1999)
IEC 60050-88, IEV: International Electrotechnical Vocabulary. Radiology and radiological physics.
IEC 60601-1, Electromedical equipment — Part 1: General instructions pertaining to safety
IEC 61000-4-2, Electromagnetic compatibility (EMV) — Part 4-2: Test and measurement procedure; Test of
immunity against static electric discharges
IEC 61000-4-3, Electromagnetic compatibility (EMC) — Part 4-3: Testing and measurement techniques -
Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-4, Electromagnetic compatibility (EMC) - Part 4-4: Testing and measurement techniques -
Electrical fast transient/burst immunity test
IEC 61000-4-5, Electromagnetic compatibility (EMC) — Part 4-5: Testing and measurement techniques -
Surge immunity test
IEC 61000-4-6, Electromagnetic compatibility (EMC) — Part 4-6: Testing and measurement techniques -
Immunity to conducted disturbances, induced by radio-frequency fields
IEC 61000-4-8, Electromagnetic compatibility (EMC) — Testing and measurement techniques - Power
frequency magnetic field immunity test
IEC 61000-4-11, Testing and measurement techniques - Voltage dips, short interruptions and voltage
variations immunity tests
© ISO 2014 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 28057:2018
ISO 28057:2014(E)
IEC 61000-6-2, Electromagnetic compatibility (EMC) — Part 6-2: Generic standards - Immunity for
industrial environments
IEC 61187, Electrical and electronic measuring equipment — Documentation
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
absorbed dose
energy imparted to matter in a suitably small element of volume by ionizing radiation, divided by the
mass of that element of volume
3.2
background value
M
0
indicated value (3.16) of a TLD system (3.46) during evaluation of a non-irradiated
TL detector (3.45) according to the operating instructions
Note 1 to entry: A change in the background value (3.2) can be caused by a change in the TL-indicating instrument
(3.47), by an insufficient pre-irradiation annealing (3.28), or by contamination of the detector (3.45).
3.3
batch
number of TL detectors (3.45) of the same type originating from the same
manufacturing process and corresponding in their entirety both to the requirements defined in this
International Standard and to the quality properties guaranteed by the manufacturer with regard to
their response (3.39), their individual variation (3.17), and their nonlinearity (3.24)
3.4
calibration
determination of the correlation between the indicated value (3.16) of a TL
detector (3.45) and the conventional true value of the measured quantity (3.20), absorbed dose (3.1) to
water, under reference conditions (3.32)
Note 1 to entry: Calibration serves to determine or check the calibration coefficient (3.5). The conventional true
value of the measured quantity (3.20) is given by the measured value (3.21) determined directly or indirectly with
a primary standard.
3.5
calibration coefficient
N
i
relation valid under reference conditions (3.32)
D
N =
i
MM−
i 0
in this formula, D is the conventional true value of the measured quantity (3.20), M − M is the difference
i 0
resulting from the indicated value (3.16) of a single TL detector (3.45)i and the background value (3.2)
Note 1 to entry: Thus, the calibration coefficient (3.5) is the reciprocal value of the response (3.39) under reference
conditions (3.32).
2 © ISO 2014 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 28057:2018
ISO 28057:2014(E)
3.6
casing
capsule, usually made from PMMA of 1 mm front wall thickness and shaped as a flat circular cylinder, in
which a small set of TL detectors (3.45) can be placed in the same plane
Note 1 to entry: The setup consisting of the detectors (3.45) and the casing (3.6) is the TL probe (3.48).
3.7
conditioning of a batch
conditioning
multiple irradiation and pre-irradiation annealing (3.28) of a batch (3.3) of TL detectors (3.45)
Note 1 to entry: Whether conditioning (3.7) is sufficient is examined by the reusability (3.40) test according to
5.3.3.
3.8
correction factor
factor applied to the indicated value (3.16) in order to compensate for the
measurement deviation caused by an influence quantity (3.18) or by the measured quantity (3.20)
Note 1 to entry: Examples for using a correction factor (3.8) are the corrections for fading (3.13), energy dependence
(3.12), and nonlinearity (3.24) (see 4.4.5).
3.9
correction summand
summand added to the indicated value (3.16) in order to compensate for the measurement deviation
caused by an influence quantity (3.18)
Note 1 to entry: The background value (3.2) is an example for corrections using a correction summand (3.9) (see
4.4.2).
3.10
directional dependence of response
directional dependence
dependence of the response (3.39) of a TL detector (3.45) on the direction of
radiation incidence
3.11
direction of preference
direction referring to the TL detector (3.45) or TL probe (3.48) that is considered as a reference value for
the direction of radiation incidence as an influence quantity (3.18)
3.12
energy dependence of response
energy dependence
dependence of the response (3.39) of a TL detector (3.45) on radiation quality (3.30)
3.13
fading
F
quotient of the alteration of the measured value (3.21) of the absorbed dose (3.1) during the time interval
between the end of irradiation and evaluation, e.g. caused by the influence of ambient temperature, and
the value of the absorbed dose (3.1) measured immediately after irradiation
Note 1 to entry: Fading (3.13) is expressed as a percentage.
Note 2 to entry: The alteration of the measured absorbed dose (3.1) may be positive (increment) or negative
(decrement).
© ISO 2014 – All rights reserved 3
---------------------- Page: 15 ----------------------
SIST EN ISO 28057:2018
ISO 28057:2014(E)
3.14
fading rate
.
F
fading (3.13) per time interval
3.15
glow curve
measured value (3.21) of the light emission of the TL detector (3.45) as a function
of the temperature or time during the evaluation process
3.16
indicated value
M
numerical value of a parameter displayed by a TL-indicating instrument (3.47)
Note 1 to entry: The indicated value (3.16), M, for a TL detector (3.45) is assessed from the glow curve (3.15) by
the TL-indicating instrument (3.47) (see 4.3.8.3). The measured value (3.21) of the dose is determined from the
indicated value (3.16) by applying the calibration coefficient (3.5), the correction factors (3.8), and the correction
summands (3.9) (see 4.4).
Note 2 to entry: The indicated value (3.16) is also termed the reading of the TL-indicating instrument (3.47).
3.17
individual variation of the response
individual variation
deviation of the response (3.39) of single TL detectors (3.45) from the mean response (3.39) of a batch
(3.3) of TL detectors (3.45) under identical irradiation and evaluation conditions
3.18
influence quantity
a quantity which is not a measured quantity (3.20) but nevertheless influences
the result of a measurement
Note 1 to entry: Influence quantities (3.18) can develop influences as external disturbances (temperature, humidity,
line voltage, etc.), as properties inherent to the instrument, i.e. caused by the instrument itself (zero drift, aging of
the system components, post-irradiation stabilization, etc.), or as adjustable quantities affecting the result of the
measurement [e.g. radiation quality (3.30) or direction of radiation incidence during dose measurement].
Note 2 to entry: The correction of the impact of an influence quantity (3.18) may require the application to the
indicated value (3.16) of a correction factor (3.8) [multiplicative influence quantity (3.18), e.g. fading (3.13)] or of a
correction summand (3.9) [additive influence quantity (3.18), e.g. background value (3.2)].
Note 3 to entry: If an influence quantity (3.18) is not taken into account by applying a correction factor (3.8) or a
correction summand (3.9), the correction factor (3.8) is set equal to one or the correction summand (3.9) is set equal
to zero, respectively.
3.19
linear energy transfer
LET
average energy locally imparted to a medium by a charged particle of a specified energy along a suitably
small element of its path, divided by that element
Note 1 to entry: The value of LET (in keV/µm) is usually stated for water as the medium traversed by the charged
particle.
[SOURCE: ICRU 60]
4 © ISO 2014 – All rights reserved
---------------------- Page: 16 ----------------------
SIST EN ISO 28057:2018
ISO 28057:2014(E)
3.20
measured quantity
physical quantity to be determined by the measuring system
Note 1 to entry: According to ICRU 62, the measured quantity in clinical dosimetry is the absorbed dose (3.1) to
water at the point of measurement (3.26).
3.21
measured value of a TLD system
measured value
value of the measured quantity (3.20), absorbed dose (3.1) to water, determined
with a TLD system (3.46) at the point of measurement (3.26)
Note 1 to entry: The measured value (3.21) is determined as the product of the correction factors (3.8) and the
mean of the indicated values (3.16) of the single TL detectors (3.45), located at and irradiated together at the same
time in the TL probe (3.48), corrected for the background value (3.2), and multiplied by the individual calibration
coefficient (3.5).
3.22
measurement cycle
sequence of working steps in TL dosimetry consisting of pre-irradiation annealing (3.28), irradiation,
post-irradiation annealing (3.27), and evaluation of TL detectors (3.45)
3.23
measuring range
range of dose values in which the TLD system (3.46) meets the requirements for
the operation characteristics
Note 1 to entry: The limits of the measuring range of a TLD system (3.46) are within the interval spanned by the
smallest and the highest measured value (3.21
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.