ASTM ISO/ASTM51261-13(2020)
(Practice)Standard Practice for Calibration of Routine Dosimetry Systems for Radiation Processing
Standard Practice for Calibration of Routine Dosimetry Systems for Radiation Processing
SIGNIFICANCE AND USE
4.1 Ionizing radiation is used to produce various desired effects in products. Examples of applications include the sterilization of medical products, microbial reduction, modification of polymers and electronic devices, and curing of inks, coatings, and adhesives (4).
4.2 Absorbed-dose measurements, with statistical controls and documentation, are necessary to ensure that products receive the desired absorbed dose. These controls include a program that addresses requirements for calibration of routine dosimetry system.
4.3 A routine dosimetry system calibration procedure as described in this document provides the user with a dosimetry system whose dose measurements are traceable to national or international standards for the conditions of use (see Annex A4). The dosimetry system calibration is part of the user’s measurement management system.
SCOPE
1.1 This practice specifies the requirements for calibrating routine dosimetry systems for use in radiation processing, including establishing measurement traceability and estimating uncertainty in the measured dose using the calibrated dosimetry system.
Note 1: Regulations or other directives exist in many countries that govern certain radiation processing applications such as sterilization of healthcare products and radiation processing of food requiring that absorbed-dose measurements be traceable to national or international standards (ISO 11137-1, Refs (1-3)2).
1.2 The absorbed-dose range covered is up to 1 MGy.
1.3 The radiation types covered are photons and electrons with energies from 80 keV to 25 MeV.
1.4 This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and describes a means of achieving compliance with the requirements of ASTM E2628 “Practice for Dosimetry in Radiation Processing” for the calibration of routine dosimetry systems. It is intended to be read in conjunction with ASTM E2628 and the relevant ASTM or ISO/ASTM standard practice for the dosimetry system being calibrated referenced in Section 2.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ISO/ASTM 51261:2013 (Reapproved 2020)(E)
Standard Practice for
Calibration of Routine Dosimetry Systems for Radiation
Processing
This standard is issued under the fixed designation ISO/ASTM 51261; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
1. Scope 2. Referenced documents
1.1 This practice specifies the requirements for calibrating 2.1 ASTM Standards:
routine dosimetry systems for use in radiation processing, E170Terminology Relating to Radiation Measurements and
includingestablishingmeasurementtraceabilityandestimating Dosimetry
uncertainty in the measured dose using the calibrated dosim- E178Practice for Dealing With Outlying Observations
etry system. E2628Practice for Dosimetry in Radiation Processing
NOTE 1—Regulations or other directives exist in many countries that
E2701Guide for Performance Characterization of Dosim-
govern certain radiation processing applications such as sterilization of
eters and Dosimetry Systems for Use in Radiation Pro-
healthcare products and radiation processing of food requiring that
cessing
absorbed-dose measurements be traceable to national or international
2.2 ISO/ASTM Standards:
standards (ISO 11137-1, Refs (1-3) ).
51607Practice for Use of an Alanine-EPR Dosimetry Sys-
1.2 The absorbed-dose range covered is up to 1 MGy.
tem
1.3 The radiation types covered are photons and electrons
51707Guide for Estimating Uncertainties in Dosimetry for
with energies from 80 keV to 25 MeV.
Radiation Processing
1.4 This document is one of a set of standards that provides
2.3 International Commission on Radiation Units and Mea-
recommendations for properly implementing dosimetry in
surements Reports:
radiation processing, and describes a means of achieving
ICRU Report 85aFundamental Quantities and Units for
compliance with the requirements of ASTM E2628 “Practice
Ionizing Radiation
for Dosimetry in Radiation Processing” for the calibration of 5
2.4 ISO Standards:
routinedosimetrysystems.Itisintendedtobereadinconjunc-
ISO 11137-1 Sterilization of health care products—
tion withASTM E2628 and the relevantASTM or ISO/ASTM
Radiation—Requirements for the development, validation
standard practice for the dosimetry system being calibrated
and routine control of a sterilization process for medical
referenced in Section 2.
devices
1.5 This standard does not purport to address all of the 5
2.5 ISO/IEC Standards:
safety concerns, if any, associated with its use. It is the
17025General Requirements for the Competence ofTesting
responsibility of the user of this standard to establish appro-
and Calibration Laboratories
priate safety, health, and environmental practices and deter-
2.6 Joint Committee for Guides in Metrology (JCGM)
mine the applicability of regulatory limitations prior to use.
Reports:
1.6 This international standard was developed in accor-
JCGM 100:2008, GUM 1995, with minor corrections,
dance with internationally recognized principles on standard-
Evaluation of measurement data – Guide to the Expres-
ization established in the Decision on Principles for the
sion of Uncertainty in Measurement
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
www.astm.org, or contact ASTM Customer Service at service@astm.org. For
This practice is under the jurisdiction of ASTM Committee E61 on Radiation Annual Book of ASTM Standards volume information, refer to the standard’s
Processing and is the direct responsibility of Subcommittee E61.01 on Dosimetry, Document Summary page on the ASTM website.
and is also under the jurisdiction of ISO/TC 85/WG 3. Available from International Commission on Radiation Units and
Current edition approved Oct. 1, 2020. Published November 2020. Originally Measurements, 7910 Woodmont Avenue, Suite 800, Bethesda, MD 20814, USA.
published asASTM E1261–88. Last previousASTM edition E1261–00.ASTM Available from International Organization for Standardization (ISO), 1, ch. de
ε1
E 1261–94 was adopted by ISO in 1998 with the intermediate designation ISO la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
15556:1998(E). The present International Standard ISO/ASTM 51261:2013(20)(E) www.iso.ch.
replacesandisareapprovalofthelastpreviouseditionISO/ASTM51261:2013(E). DocumentproducedbyWorkingGroup1oftheJointCommitteeforGuidesin
The boldface numbers given in parentheses refer to the bibliography at the end Metrology (JCGM/WG 1). Available free of charge at the BIPM website (http://
of this guide. www.bipm.org).
© ISO/ASTM International 2020 – All rights reserved
ISO/ASTM 51261:2013 (2020)(E)
3. Terminology 3.1.12 measurement management system—set of inter-
related or interacting elements necessary to achieve metrologi-
3.1 Definitions:
cal confirmation and continual control of measurement pro-
3.1.1 approved laboratory—laboratory that is a recognized
cesses.
nationalmetrologyinstitute;orhasbeenformallyaccreditedto
3.1.13 primary standard dosimetry system—dosimetry sys-
ISO/IEC 17025; or has a quality system consistent with the
tem that is designated or widely acknowledged as having the
requirements of ISO/IEC 17025.
highest metrological qualities and whose value is accepted
3.1.1.1 Discussion—A recognized national metrology insti-
without reference to other standards of the same quantity.
tute or other calibration laboratory accredited to ISO/IEC
3.1.14 reference standard dosimetry system—dosimetry
17025 should be used in order to ensure traceability to a
system, generally having the highest metrological quality
national or international standard. A calibration certificate
available at a given location or in a given organization, from
provided by a laboratory not having formal recognition or
which measurements made there are derived.
accreditation will not necessarily be proof of traceability to a
national or international standard.
3.1.15 routine dosimetry system—dosimetry system cali-
brated against a reference standard dosimetry system and used
3.1.2 calibration—set of operations that establish, under
for routine absorbed dose measurements, including dose map-
specified conditions, the relationship between values of quan-
ping and process monitoring.
tities indicated by a measuring instrument or measuring
3.1.16 traceability—propertyoftheresultofameasurement
system, or values represented by a material measure or a
or the value of a standard whereby it can be related to stated
reference material, and the corresponding values realized by
references, usually national or international standards, through
standards.
an unbroken chain of comparisons all having stated uncertain-
3.1.3 calibration curve—expression of the relation between
ties.
indication and the corresponding measured quantity value.
3.1.16.1 Discussion—Measurementtraceabilityisarequire-
3.1.4 charged-particle equilibrium (referred to as electron
ment of any measurement management system (see Annex
equilibriumin the case of electrons set in motion by photon A4).
beam irradiation of a material)—condition in which the kinetic
3.1.17 transfer standard dosimetry system—dosimetry sys-
energy of charged particles (or electrons), excluding rest mass,
tem used as an intermediary to calibrate other dosimetry
entering an infinitesimal volume of the irradiated material
systems.
equals the kinetic energy of charged particles (or electrons)
3.1.18 type I dosimeter—dosimeter of high metrological
emerging from it.
quality, the response of which is affected by individual influ-
3.1.5 dosimeter batch—quantity of dosimeters made from a
ence quantities in a well-defined way that can be expressed in
specific mass of material with uniform composition, fabricated
terms of independent correction factors.
in a single production run under controlled, consistent
3.1.19 type II dosimeter—dosimeter, the response of which
conditions, and having a unique identification code.
isaffectedbyinfluencequantitiesinacomplexwaythatcannot
3.1.6 dosimeter stock—partofadosimeterbatchheldbythe
practically be expressed in terms of independent correction
user.
factors.
3.1.7 dosimetry system—system used for measuring ab- 3.1.20 uncertainty (of measurement)—parameter associated
sorbed dose, consisting of dosimeters, measurement instru- with the result of a measurement that characterizes the disper-
sion of the values that could reasonably be attributed to the
ments and their associated reference standards, and procedures
measurand or derived quantity.
for the system’s use.
3.1.21 uncertainty budget—quantitative analysis of the
3.1.8 electron equilibrium—chargedparticleequilibriumfor
component terms contributing to the uncertainty of a
electrons. (See charged-particle equilibrium.)
measurement, including their statistical distribution, math-
3.1.9 influence quantity—quantity that is not the measurand
ematical manipulation and summation.
but that affects the result of the measurement.
3.2 validation (of a process)—establishment of documented
3.1.10 in-situ/in-plant calibration—calibration where the
evidence, which provides a high degree of assurance that a
dosimeter irradiation is performed in the place of use of the
specified process will consistently produce a product meeting
routine dosimeters.
its predetermined specifications and quality attributes.
3.1.10.1 Discussion—In-situ/in-plant calibration of dosim-
3.3 verification—confirmation by examination of objective
etry systems refers to irradiation of dosimeters along with
evidence that specified requirements have been met.
reference or transfer standard dosimeters, under operating
3.3.1 Discussion—In the case of measuring equipment, the
conditions that are representative of the routine processing
result of verification leads to a decision either to restore to
environment, for the purpose of developing a calibration curve
service or to perform adjustments, repair, downgrade, or
for the routine dosimetry systems.
declare obsolete. In all cases it is required that a written trace
3.1.11 measurand—specific quantity subject to measure- of the verification performed be kept on the instrument’s
ment. individual record.
© ISO/ASTM International 2020 – All rights reserved
ISO/ASTM 51261:2013 (2020)(E)
bration curve generated under conditions that are representative of the
3.4 Definitions of other terms used in this standard that
routineprocessingenvironment.Anin-situ/in-plantcalibrationmaynotbe
pertain to radiation measurement and dosimetry may be found
valid or may require calibration verification if the calibration conditions
in ASTM Terminology E170. Definitions in ASTM Terminol-
can not be maintained during routine use. For example, the calibration
ogy E170 are compatible with ICRU Report 85a; that
irradiations are carried out as a single exposure, but the dosimeter is used
document, therefore, may be used as an alternative reference.
for dose measurement of fractionated irradiations.
5.3 Uncertainties:
4. Significance and use
5.3.1 Allmeasurementsofabsorbeddoseneedtobeaccom-
4.1 Ionizing radiation is used to produce various desired panied by an estimate of uncertainty (see ISO/ASTM 51707,
effects in products. Examples of applications include the
Refs (5,6) and GUM).
sterilization of medical products, microbial reduction, modifi-
5.3.2 All components of uncertainty should be included in
cation of polymers and electronic devices, and curing of inks,
the estimate, including those arising from calibration, dosim-
coatings, and adhesives (4).
eter reproducibility, instrument stability and the effect of
influencequantities.Afullquantitativeanalysisofcomponents
4.2 Absorbed-dose measurements, with statistical controls
of uncertainty is referred to as an uncertainty budget and is
and documentation, are necessary to ensure that products
often presented in the form of a table. Typically, the uncer-
receive the desired absorbed dose. These controls include a
tainty budget will identify all significant components of uncer-
program that addresses requirements for calibration of routine
tainty together with their methods of estimation, statistical
dosimetry system.
distributions and magnitudes.
4.3 A routine dosimetry system calibration procedure as
5.3.3 Examples of components of uncertainty in the dosim-
described in this document provides the user with a dosimetry
etry system calibration include inherent variation in dosimeter
system whose dose measurements are traceable to national or
response, uncertainty in the calibration irradiation dose, uncer-
international standards for the conditions of use (see Annex
tainty in the calibration curve fit and uncertainty in dosimeter
A4). The dosimetry system calibration is part of the user’s
response correction parameters such as dosimeter thickness,
measurement management system.
dosimetermass,unirradiatedresponseandirradiationtempera-
ture.
5. Dosimeter system calibration overview
5.3.4 Additional components of uncertainty might be pres-
5.1 Calibrationofaroutinedosimetrysystemconsistsofthe
entwhentheconditionsofusearedifferentthantheconditions
following:
of calibration. In these instances, a calibration verification is
5.1.1 Selection of the calibration dosimeters from the user
conducted to quantify a component of uncertainty to account
stock (see Section 8).
for these differences (see 9.1.8 and 9.2.9).
5.1.2 Irradiation of the calibration dosimeters (see 9.1 and
9.2).
6. Requirements for a routine dosimetry system
5.1.3 Calibration and/or performance verification of mea-
calibration
surement instruments (see Section 7).
6.1 Dosimetry system calibration shall be conducted for
5.1.4 Measurement of the calibration dosimeters response
each new dosimeter batch.
(see 9.1.6 and 9.2.5.1).
NOTE 4—The response of different dosimeter stocks purchased at
5.1.5 Analysis of the calibration dosimeter response data
different times from a given dosimeter batch should be verified to ensure
(see 9.1.7 and 9.2.6).
equivalent response.Astatistical test should be used to determine if there
5.1.6 Verification of the calibration curve for conditions of
is any significant difference between the stocks. This should be repeated
at several doses over the calibration dose range.
use, if appropriate (see 9.1.8 and Note 2).
5.1.7 Estimation of the combined uncertainty for the condi-
6.2 Routinedosimetrysystemsshallbecalibratedusingone
tions of use (see 9.1.10 and 9.2.7).
of the methods described in 9.1 and 9.2.
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