ASTM ISO/ASTM52628-20

Standard Practice for Dosimetry in Radiation Processing

SIGNIFICANCE AND USE
4.1 Radiation processing of articles in both commercial and research applications may be carried out for a number of purposes. These include, for example, sterilization of health care products, reduction of the microbial populations in foods and modification of polymers. The radiations used may be accelerated electrons, gamma-radiation from radionuclide sources such as cobalt-60, or X-radiation.  
4.2 To demonstrate control of radiation processes that are dependent on the delivery of a known dose, the absorbed dose must be measured using a dosimetry system, the calibration of which, is traceable to appropriate national or international standards. The radiation-induced change in the dosimeter is evaluated and related to absorbed dose through calibration. Dose measurements required for particular processes are described in other standards referenced in this practice.
SCOPE
1.1 This practice describes the basic requirements that apply when making absorbed dose measurements in accordance with the ASTM E61 series of dosimetry standards. In addition, it provides guidance on the selection of dosimetry systems and directs the user to other standards that provide specific information on individual dosimetry systems, calibration methods, uncertainty estimation and radiation processing applications.  
1.2 This practice applies to dosimetry for radiation processing applications using electrons or photons (gamma- or X-radiation).  
1.3 This practice addresses the minimum requirements of a measurement management system, but does not include general quality system requirements.  
1.4 This practice does not address personnel dosimetry or medical dosimetry.  
1.5 This practice does not apply to primary standard dosimetry systems.  
1.6 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.

General Information

• Status: Published
• Publication Date: 14-Feb-2020
• ICS: 17.240 - Radiation measurements
• Technical Committee: E61 - Radiation Processing
• Drafting Committee: E61.01 - Dosimetry

Relations

• Refers: ASTM F1355-19 - Standard Guide for Irradiation of Fresh Agricultural Produce as a Phytosanitary Treatment
• Effective Date: 01-Dec-2019
• Refers: ASTM F1885-18 - Standard Guide for Irradiation of Dried Spices, Herbs, and Vegetable Seasonings to Control Pathogens and Other Microorganisms
• Effective Date: 01-Nov-2018
• Refers: ASTM E3083-17 - Standard Terminology Relating to Radiation Processing: Dosimetry and Applications
• Effective Date: 01-Oct-2017
• Refers: ASTM F1355-06(2014) - Standard Guide for Irradiation of Fresh Agricultural Produce as a Phytosanitary Treatment
• Effective Date: 01-Jun-2014
• Refers: ASTM F1885-04(2010) - Standard Guide for Irradiation of Dried Spices, Herbs, and Vegetable Seasonings to Control Pathogens and Other Microorganisms
• Effective Date: 01-Dec-2010
• Refers: ASTM E2232-10 - Standard Guide for Selection and Use of Mathematical Methods for Calculating Absorbed Dose in Radiation Processing Applications
• Effective Date: 01-Jul-2010
• Refers: ASTM F1736-09 - Standard Guide for Irradiation of Finfish and Aquatic Invertebrates Used as Food to Control Pathogens and Spoilage Microorganisms
• Effective Date: 01-Feb-2009
• Refers: ASTM F1356-08 - Standard Practice for Irradiation of Fresh and Frozen Red Meat and Poultry to Control Pathogens and Other Microorganisms
• Effective Date: 01-Jan-2008
• Refers: ASTM F1355-06 - Standard Guide for Irradiation of Fresh Agricultural Produce as a Phytosanitary Treatment
• Effective Date: 01-Jan-2006
• Refers: ASTM F1885-04 - Standard Guide for Irradiation of Dried Spices, Herbs, and Vegetable Seasonings to Control Pathogens and Other Microorganisms
• Effective Date: 01-Jan-2004
• Refers: ASTM F1736-03 - Standard Guide for Irradiation of Finfish and Aquatic Invertebrates Used as Food to Control Pathogens and Spoilage Microorganisms
• Effective Date: 10-Jul-2003
• Refers: ASTM E2232-02 - Standard Guide for Selection and Use of Mathematical Methods for Calculating Absorbed Dose in Radiation Processing Applications
• Effective Date: 10-Sep-2002
• Refers: ASTM F1356-99 - Standard Guide for the Irradiation of Fresh and Frozen Red Meat and Poultry to Control Pathogens and Other Microorganisms
• Effective Date: 30-Dec-1999
• Refers: ASTM F1355-99 - Standard Guide for Irradiation of Fresh Fruits as a Phytosanitary Treatment
• Effective Date: 30-Dec-1999
• Refers: ASTM F1885-98 - Standard Guide for Irradiation of Dried Spices, Herbs, and Vegetable Seasonings to Control Pathogens and Other Microorganisms
• Effective Date: 10-May-1998

Overview

ASTM ISO/ASTM52628-20 - Standard Practice for Dosimetry in Radiation Processing outlines the essential requirements and best practices for measuring absorbed doses in radiation processing. Developed by ASTM and harmonized with international ISO standards, this standard supports the safe and effective use of ionizing radiation technologies. It provides foundational guidance for selecting and calibrating dosimetry systems, vital for process control in diverse industries such as food sterilization, healthcare product treatment, and polymer modification. By focusing on absorbed dose measurement traceable to national or international standards, the standard fosters consistent, high-quality outcomes and regulatory compliance in radiation processing.

Key Topics

• Dosimetry Systems: Provides criteria for choosing appropriate dosimetry systems based on dose range, radiation type, energy, spatial resolution, and uncertainty level. Addresses both type I dosimeters (with easily corrected responses) and type II dosimeters (with complex influencing factors).
• Calibration and Traceability: Emphasizes the need for routine calibration of dosimetry systems, ensuring that dose measurements are traceable to recognized standards for reliable results.
• Measurement Management: Supplies minimum requirements for measurement management systems specific to dosimetry, excluding broader quality system mandates.
• Uncertainty Estimation: Guides users in evaluating and documenting the uncertainty associated with dose measurements, supported by references to internationally recognized methodologies.
• Classification and Documentation: Distinguishes reference and routine dosimetry systems and underscores rigorous documentation practices for compliance and process verification.
• Exclusions: Does not cover personnel or medical dosimetry, nor apply to primary standard dosimetry systems.

Applications

ASTM ISO/ASTM52628-20 is critical in industries and research settings requiring precise radiation dosage for reliable process outcomes. Major applications include:

• Healthcare Product Sterilization: Ensures the delivery of validated, traceable irradiation doses for sterilizing medical devices, minimizing risks of contamination.
• Food Irradiation: Verifies the reduction of microbial populations in foods, supporting food safety and compliance with international phytosanitary standards.
• Polymer Modification: Assures tailored radiation treatment for modifying materials’ physical or chemical properties, enhancing product performance.
• Industrial Process Monitoring: Supports dose mapping and qualification of irradiation facility operations (installation, operational, and performance qualification), underpinning routine monitoring and quality assurance.
• Specialized Radiation Processes: Facilitates absorbed dose measurement in processes like blood irradiation, insect sterilization for pest control, and research studies on irradiated materials.

Related Standards

ASTM ISO/ASTM52628-20 is supported by a suite of referenced and related standards that provide detailed protocols for specific dosimetry systems and applications:

• Calibration and Dosimetry System Standards:

  • ISO/ASTM 51261: Calibration of Routine Dosimetry Systems
  • ISO/ASTM 51275: Radiochromic Film Dosimetry Systems
  • ISO/ASTM 51276: Polymethylmethacrylate Dosimetry Systems
  • ISO/ASTM 51401: Dichromate Dosimetry Systems
  • ISO/ASTM 51607: Alanine-EPR Dosimetry Systems

• Application-Specific Guides:

  • ISO 11137 series: Radiation sterilization for medical devices
  • ISO 14470: Food irradiation requirements
  • ISO/ASTM 51939: Blood irradiation dosimetry
  • ISO/ASTM 51940: Dosimetry for sterile insect release

• Uncertainty and Measurement Management:

  • ISO/ASTM 51707: Estimation of Measurement Uncertainty
  • ISO 10012: Measurement management systems
  • ISO/IEC 17025: Competence of calibration laboratories

• Additional Guidance:

  • ISO/ASTM 52303: Absorbed dose mapping
  • ASTM E2232: Mathematical methods for calculating absorbed dose

By integrating ASTM ISO/ASTM52628-20 with these standards, organizations can establish robust, traceable, and internationally recognized radiation processing protocols, optimizing safety, efficacy, and regulatory compliance.

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 52628:2020(E)
Standard Practice for
Dosimetry in Radiation Processing
This standard is issued under the fixed designation ISO/ASTM 52628; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
Note—To keep year dates consistent, this 2020 edition is a re-issue of ISO/ASTM 52628-19, which was
inadvertently published before ISO formal approval. It is technically identical with the exception of the year date.
INTRODUCTION
The use of ionizing radiation for the treatment of commercial products such as the sterilization of healthcare
products, the reduction of microbial contamination in food or the modification of polymers is referred to as radiation
processing. The types of radiation used may be gamma radiation (typically from cobalt-60 sources), X-radiation or
accelerated electrons.
In some applications, it is necessary to ensure that the specified absorbed dose is applied. In these cases, the
absorbed dose must be measured, and measurement systems have been developed for this purpose. Much of the
developmentofthesesystemsrestsontheearlydevelopmentofdosimetrysystemsforpersonnelradiationprotection
and for medical treatment. However, the absorbed doses used in radiation processing are generally higher, ranging
from ~10 Gy up to 100 kGy or more and new dosimetry systems have been developed for measurements of these
doses.
Note that the terms “dose” and “absorbed dose” are used interchangeably in this standard (see 3.1.1).
The dose measurements required in radiation processing concern characterization of radiation facilities in
installation qualification (IQ) and operational qualification (OQ), measurement of dose distribution in irradiated
products in performance qualification (PQ) and routine monitoring of the irradiation process.
The literature is abundant with articles on dosimeters for radiation processing, and guidelines and standards have
been written by several organizations (the International Atomic Energy Agency (IAEA) and the International
CommissiononRadiationUnitsandMeasurements(ICRU),forexample)fortheoperationofthedosimetrysystems
and for their use in the characterization and validation of the radiation processing applications. In particular, ICRU
Report 80 provides information on the scientific basis and historical development of many of the systems in current
use.
ASTM Subcommittee E10.01 on Radiation Processing: Dosimetry andApplications was formed in 1984 initially
with the scope of developing standards for food irradiation, but its scope was widened to include all radiation
processing applications. The subcommittee, now Committee E61, has under its jurisdiction approximately 30
standard practices and standard guides, collectively known as the E61 standards on radiation processing.Anumber
of these standards have been published as ISO/ASTM standards, thereby ensuring a wider international acceptance.
These practices and guides describe the dosimetry systems most commonly used in radiation processing, and the
dose measurements that are required in the validation and routine monitoring of the radiation processes. A current
list of the E61 standards on radiation processing is given in 2.1 and 2.2.
The development, validation and routine control of a radiation process comprise a number of activities, most of
which rely on the ability to measure the delivered dose accurately. It is therefore necessary that dose is measured
with traceability to national, or international, standards, and the uncertainty in measured dose is known, including
the effect of influence quantities. The E61 standards on radiation processing dosimetry serve to fulfill these
requirements.
The practices describing dosimetry systems have several common attributes, and there is a need to have one
general standard that can act as a common reference and that can be used as a basis for the selection of dosimetry
systems for defined tasks. ISO/ASTM Practice 52628 serves this purpose. It outlines general requirements for the
calibration and use of dosimetry systems and for the estimation of measurement uncertainties. Details relating to
each dosimetry system are found in the respective standards and each of these refer to ISO/ASTM Practice 52628
for the general requirements.
© ISO/ASTM International 2020 – All rights reserved
ISO/ASTM 52628:2020(E)
1. Scope 51261 Practice for Calibration of Routine Dosimetry Sys-
tems for Radiation Processing
1.1 Thispracticedescribesthebasicrequirementsthatapply
51275 Practice for Use of a Radiochromic Film Dosimetry
when making absorbed dose measurements in accordance with
System
the ASTM E61 series of dosimetry standards. In addition, it
51276 Practice for Use of a Polymethylmethacrylate Dosim-
provides guidance on the selection of dosimetry systems and
etry System
directs the user to other standards that provide specific infor-
51310 Practice for Use of a Radiochromic Optical Wave-
mation on individual dosimetry systems, calibration methods,
guide Dosimetry System
uncertainty estimation and radiation processing applications.
51401 Practice for Use of a Dichromate Dosimetry System
1.2 This practice applies to dosimetry for radiation process-
51538 Practice for Use of the Ethanol-Chlorobenzene Do-
ing applications using electrons or photons (gamma- or
simetry System
X-radiation).
51540 Practice for Use of a Radiochromic Liquid Dosimetry
System
1.3 This practice addresses the minimum requirements of a
measurement management system,butdoesnotincludegeneral 51607 Practice for Use of an Alanine-EPR Dosimetry Sys-
quality system requirements. tem
51608 Practice for Dosimetry in an X-Ray (Bremsstrahlung)
1.4 This practice does not address personnel dosimetry or
Facility for Radiation Processing at Energies between 50
medical dosimetry.
keV and 7.5 MeV
1.5 This practice does not apply to primary standard dosim-
51631 Practice for Use of Calorimetric Dosimetry Systems
etry systems.
for Electron Beam Dose Measurements and Dosimetry
1.6 This standard does not purport to address all of the System Calibration
safety concerns, if any, associated with its use. It is the 51649 Practice for Dosimetry in an Electron Beam Facility
responsibility of the user of this standard to establish appro- for Radiation Processing at Energies Between 300 keV
priate safety, health, and environmental practices and deter- and 25 MeV
mine the applicability of regulatory limitations prior to use. 51650 Practice for Use of a Cellulose Triacetate Dosimetry
System
2. Referenced documents
51702 Practice for Dosimetry in a Gamma Facility for
2 Radiation Processing
2.1 ASTM Standards:
51707 Guide for Estimation of Measurement Uncertainty in
E2232 Guide for Selection and Use of Mathematical Meth-
Dosimetry for Radiation Processing
ods for Calculating Absorbed Dose in Radiation Process-
51818 Practice for Dosimetry in an Electron Beam Facility
ing Applications
for Radiation Processing at Energies Between 80 and 300
E3083 Terminology Relating to Radiation Processing: Do-
keV
simetry and Applications
51900 Guide for Dosimetry in Radiation Research on Food
F1355 GuideforIrradiationofFreshAgriculturalProduceas
and Agricultural Products
a Phytosanitary Treatment
51939 Practice for Blood Irradiation Dosimetry
F1356 Guide for Irradiation of Fresh, Frozen or Processed
51940 Guide for Dosimetry for Sterile Insect Release
Meat and Poultry to Control Pathogens and Other Micro-
Programs
organisms
51956 PracticeforUseofaThermoluminescence-Dosimetry
F1736 Guide for Irradiation of Finfish and Aquatic Inverte-
(TLD) System for Radiation Processing
brates Used as Food to Control Pathogens and Spoilage
52116 Practice for Dosimetry for a Self-Contained Dry-
Microorganisms
Storage Gamma Irradiator
F1885 Guide for Irradiation of Dried Spices, Herbs, and
52303 Guide for Absorbed Dose Mapping in Radiation
Vegetable Seasonings to Control Pathogens and Other
Processing Facilities
Microorganisms
52701 Guide for Performance Characterization of Dosim-
2.2 ISO/ASTM Standards:
eters and Dosimetry Systems for Use in Radiation Pro-
51026 Practice for Using the Fricke Dosimetry System
cessing
51205 Practice for Use of a Ceric-Cerous Sulfate Dosimetry
2.3 ISO Standards:
System
ISO 11137-1 Sterilization of health care products – Radia-
tion – Part 1: Requirements for development, validation
and routine control of a sterilization process for medical
This practice is under the jurisdiction of ASTM Committee E61 on Radiation
devices
Processing and is the direct responsibility of Subcommittee E61.01 on Dosimetry,
ISO 11137-3 Sterilization of health care products – Radia-
and is also under the jurisdiction of ISO/TC 85/WG 3.
Current edition approved September 2019. Published April 2020. Originally
tion – Part 3: Guidance on dosimetric aspects of
published as ASTM E2628-09. The present International Standard ISO/ASTM
52628–2020(E) replaces ISO/ASTM 52628–13.
For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
www.astm.org, or contact ASTM Customer Service at [e-mail]. For Available from International Organization for Standardization (ISO), 1, ch. de
Annual Book of ASTM Standards volume information, refer to the standard’s la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, https://
Document Summary page on the ASTM website. www.iso.org/contact-iso.html
© ISO/ASTM International 2020 – All rights reserved
ISO/ASTM 52628:2020(E)
development, validation and routine control effect of influence quantities, for a dosimeter or dosimetry
ISO 10012 Measurement managements systems – Require- system under defined test conditions.
ments for measurement processes and measuring equip-
3.1.6 dosimeter response (indication)—reproducible, quan-
ment
tifiablechangeproducedinthedosimeterbyionizingradiation.
ISO 14470 Food irradiation – Requirements for the
3.1.6.1 Discussion—The dosimeter response value
development, validation and routine control of the process
(indication), obtained from one or more measurements, is used
of irradiation using ionizing radiation for the treatment of
intheestimationofthedosimetricquantity.Theresponsevalue
food
(indication) may be obtained from such measurements as
ISO/IEC 17025 General requirements for the competence of
optical absorbance, intensity of EPR spectra, or electropoten-
testing and calibration laboratories
tial between solutions.
2.4 International Commission on Radiation Units and Mea-
3.1.7 dosimetry—measurement of a dosimetric quantity by
surements (ICRU) Reports:
the use of a dosimetry system.
ICRU Report 80 Dosimetry Systems for Use in Radiation
3.1.8 dosimetry system—interrelatedelementsusedformea-
Processing
suring a dosimetric quantity, including dosimeters, instruments
ICRU Report 85a Fundamental Quantities and Units for
and their associated reference standards, and procedures for
Ionizing Radiation
their use.
2.5 Joint Committee for Guides in Metrology (JCGM)
Reports:
3.1.8.1 Discussion—As discussed in ICRU-85a, dosimetric
JCGM 100:2008, GUM , 1995, with minor corrections,
quantities provide a physical measure to correlate with actual
Evaluation of measurement data – Guide to the Expres-
or potential effects.They are products of radiometric quantities
sion of Uncertainty in Measurement
and interaction coefficients. In calculations, the values of these
JCGM 200:2012, VIM , International vocabulary of metrol-
quantities and coefficients must be known, while measure-
ogy – basic and general concepts and associated terms
mentsmightnotrequirethisinformation.Dosimetricquantities
include air kerma, exposure and absorbed dose to a specified
3. Terminology
material.
3.1 Definitions: 3.1.8.2 Discussion—In radiation processing applications the
3.1.1 absorbed dose (D)—quotient of dε by dm, where dε is quantityofinterestisusuallyabsorbeddosetowater.Absorbed
¯ ¯
the mean energy imparted by ionizing radiation to matter of dose to silicon might be used in semiconductor irradiations.
mass dm, thus 3.1.9 influence quantity—quantity that, in a direct
measurement, does not affect the quantity that is actually
D 5 dε¯⁄dm
measured, but affects the relation between the indication and
ICRU 85a
the measurement result. VIM
3.1.1.1 Discussion—TheSIunitofabsorbeddoseisthegray
3.1.9.1 Discussion—In dosimetry for radiation processing,
(Gy),where1grayisequivalenttotheabsorptionof1jouleper
typical examples of influence quantities include radiation type
kilogram of the specified material (1 Gy = 1 J/kg).
and energy, irradiation temperature, dose rate and the time
3.1.2 calibration—operation that, under specified
intervalbetweenirradiationanddeterminationoftheindication
conditions, in a first step, establishes a relation between the
of the dosimeter.
quantity values with measurement uncertainties provided by
3.1.10 measurement management system—set of interre-
measurement standards and corresponding indications with
lated or interacting elements necessary to achieve metrological
associated measurement uncertainties and, in a second step,
confirmation and continual control of measurement processes.
uses this information to establish a relation for obtaining a
ISO 10012
measurement result from an indication. VIM
3.1.10.1 Discussion—See 7.6 for further details.
3.1.3 calibration curve—expression of the relation between
3.1.11 (measurement) uncertainty—non-negative parameter
indication and corresponding measured quantity value. VIM
characterizing characterizing the dispersion of the quantity
3.1.4 dosimeter—device that, when irradiated, exhibits a
values being attributed to a measurand, based on the informa-
quantifiable change that can be related to a dosimetric quantity
tion used. VIM
using appropriate measurement instrument(s) and procedures.
3.1.12 (metrological) traceability—property of a measure-
3.1.5 dosimeter characterization / dosimetry system
ment result whereby the result can be related to a reference
characterization—determination of performance
through a documented unbroken chain of calibrations, each
characteristics, such as dose range, reproducibility and the
contributing to the measurement uncertainty. VIM
3.1.13 primary standard dosimetry system —dosimetry sys-
Available from the International Commission on Radiation Units and
tem that is designated or widely acknowledged as having the
Measurements, 7910 Woodmont Ave, Suite 800, Bethesda, MD 20815, USA.
5 highest metrological qualities and whose value is accepted
Document produced by Working Group 1 of the Joint Committee for Guides in
without reference to other standards of the same quantity.
Metrology (JCGM/WG 1). Available free of charge at the BIPM website (http://
www.bipm.org).
3.1.14 radiation processing—intentionalirradiationofprod-
Document produced by Working Group 2 of the Joint Committee for Guides in
ucts or materials to preserve, modify or improve their charac-
Metrology (JCGM/WG 2). Available free of charge at the BIPM website (http://
www.bipm.org). teristics.
© ISO/ASTM International 2020 – All rights reserved
ISO/ASTM 52628:2020(E)
3.1.15 reference standard dosimetry system—dosimetry 5. Dosimetry system requirements
system, generally having the highest metrological quality
5.1 Dosimetrysystemrequirementsareanecessarypartofa
available at a given location or in a given organization, from
measurement management system.The following requirements
which measurements made there are derived.
shall be included as a minimum, but additional requirements
3.1.16 reference standard radiation field—calibrated radia- may be appropriate depending on the nature of the process.
tion field, generally having the highest metrological quality Guidance on these requirements is given in Section 7.
available at a given location or in a given organization, from 5.1.1 Theselectionanduseofaspecificdosimetrysystemin
which measurements made there are derived. a given application shall be justified and documented. The
justification shall take into account at least the following:
3.1.17 routine dosimetry system—dosimetry system cali-
dose range
brated against a reference standard dosimetry system and used
radiation type and energy
for routine absorbed dose measurements, including dose map-
effect of influence quantities
ping and process monitoring.
level of uncertainty
3.1.18 transfer standard dosimetry system—dosimetry sys-
spatial resolution
tem used as an intermediary to calibrate other dosimetry
5.1.2 The dosimetry system shall be calibrated in accor-
systems.
dance with the requirements of ISO/ASTM Practice 51261.
5.1.3 The uncertainty associated with measurements made
3.1.19 type I dosimeter—dosimeter of high metrological
with the selected dosimetry system shall be established and
quality, the response of which is affected by individual influ-
documented. All dose measurements shall be accompanied by
ence quantities in a way that is well-defined and capable of
an estimate of uncertainty. See ISO/ASTM 51707, NPLReport
expression in terms of independent correction factors.
7 8
CIRM 29 , GUM and NIST Technical Note 1297 for guid-
3.1.19.1 Discussion—See Section 6 for examples and fur-
ance.
ther details.
5.1.4 Documentation shall be established and maintained to
3.1.20 type II dosimeter—dosimeter, the response of which
ensurecompliancewiththeminimumrequirementsspecifiedin
isaffectedbyinfluencequantitiesinacomplexwaythatcannot
the ASTM or ISO/ASTM standard relevant to the specific
practically be expressed in terms of independent correction
dosimetry system. The user’s quality system might be more
factors.
detailed than these minimum requirements.
3.1.20.1 Discussion—See Section 6 for examples and fur-
ther details. 6. Classification
6.1 Classification of dosimeters and dosimetry systems in
3.1.21 uncertainty budget—statement of a measurement
uncertainty, of the components of that measurement the ASTM E61 series of dosimetry standards is based on two
distinct criteria: (1) the inherent metrological properties of the
uncertainty, and of their calculation and combination. VIM
dosimeter (see 3.1.19 and 3.1.20), and (2) the field of applica-
3.2 Definitions of other terms used in this standard that
tion of the dosimetry system (see 3.1.15 and 3.1.17). These
pertain to radiation measurement and dosimetry may be found
classifications are important in both the selection and calibra-
inASTMTerminology E3083. Definitions inASTM E3083 are
tion of dosimetry systems.
compatible with ICRU Report 85a; that document, therefore,
6.2 Classification of Dosimeters Based on Metrological
may be used as an alternative reference. Where appropriate,
Properties:
definitions used in this standard have been derived from, and
6.2.1 This classification of dosimeters is based on knowl-
are consistent with, general metrological definitions given in
edge of their inherent metrological properties. The method of
the VIM.
measurement may be important in the classification (see
below), but the classification does not include consideration of
4. Significance and use
the quality of the actual instrumentation used, or the quality of
4.1 Radiation processing of articles in both commercial and
preparation (manufacture) of the dosimeter. For example,
research applications may be carried out for a number of
acidic solutions of dichromate ions have certain inherent
purposes. These include, for example, sterilization of health
properties in terms of their response to radiation and the effect
care products, reduction of the microbial populations in foods
of irradiation temperature that means they are classified as type
and modification of polymers. The radiations used may be
I dosimeters. The actual performance of a given dosimetry
accelerated electrons, gamma-radiation from radionuclide
system based on dichromate dosimeters will depend, however,
sources such as cobalt-60, or X-radiation.
on the quality of preparation of the dosimetric solution and the
quality of the spectrophotometers used for optical absorbance
4.2 To demonstrate control of radiation processes that are
measurement.
dependent on the delivery of a known dose, the absorbed dose
must be measured using a dosimetry system, the calibration of
which, is traceable to appropriate national or international
Sharpe,P.,andMiller,A.,“GuidelinesfortheCalibrationofRoutineDosimetry
Systems for use in Radiations Processing,” NPLReport CIRM 29, Teddington, UK,
standards. The radiation-induced change in the dosimeter is
2009.
evaluated and related to absorbed dose through calibration.
Taylor, B. N., and Kuyatt, C. E., “Guidelines for Evaluating and Expressing the
Dose measurements required for particular processes are de-
Uncertainty of NIST Measurement Results,” NIST TN-1297, Gaithersburg, MD:
scribed in other standards referenced in this practice. NIST 1994.
© ISO/ASTM International 2020 – All rights reserved
ISO/ASTM 52628:2020(E)
6.2.2 Knowledge of the inherent properties of a dosimeter is system with low uncertainty and with traceability to appropri-
important when selecting a dosimeter for a particular applica- ate national or international standards.
tion. For example, when selecting a dosimeter to be used to
6.3.1.2 Reference standard dosimetry systems may take the
transferdosebetweenradiationfieldsofdifferingtemperatures,
form of systems held at a given location or they may take the
it is essential to choose a dosimeter whose response can be
form of transfer standard dosimetry systems operated by a
correctedfortheeffectofirradiationtemperature,thatis,a type
national standards laboratory or by a laboratory accredited to
I dosimeter.
ISO/IEC 17025. In the case of transfer standard dosimetry
6.2.3 In order for a dosimeter to be classified as a type I
systems, dosimeters are sent to a facility for irradiation and
dosimeter, it must be possible to apply accurate, independent,
then returned to the issuing laboratory for measurement. The
corrections to its response to account for the effects of relevant
requirement to transport dosimeters without unduly increasing
influence quantities, such as temperature, dose rate, etc., or to
measurement uncertainty restricts the type of dosimeter that
demonstrate that the influence quantity is not relevant and will
can be used. Alanine/EPR, dichromate or ceric-cerous dosim-
not affect the dosimeter’s response. The magnitude of the
etry systems are commonly used in this way.
correction, the range of values of the influence quantity over
6.3.1.3 A reference standard dosimetry system comprises
which it is applicable and the range of doses over which it is
dosimeters and the associated measurement equipment and
applicable are determined as part of dosimeter characterization
quality system documentation necessary to ensure traceability
(see 7.3). In classifying a dosimeter as a type I dosimeter,it
to appropriate national and international standards. The dosim-
may be necessary to specify the method of measurement. For
eter used in a reference standard dosimetry system is generally
example, free radicals produced in irradiated alanine can, in
a type I dosimeter, although there may be exceptions (see, for
principle, be measured by a number of different techniques,
example, ISO/ASTM 51631).
however, only the EPR technique has been shown to provide
6.3.1.4 The expanded uncertainty achievable with measure-
the high metrological quality (precision and accuracy) neces-
ments made using a reference standard dosimetry system is
sary to classify alanine as a type I dosimeter. Examples of type
typically of the order of3%(k=2). In certain specific
I dosimeters are given in Table 1.
applications, for example the use of electrons of energy below
6.2.4 The classification of a dosimeter as a type II dosimeter
1 MeV, practical limitations of the techniques may mean that
is based on the complexity of interaction between influence
the reference standard dosimetry systems have a larger uncer-
quantities, such as temperature and dose rate, which makes it
tainty.
impractical to apply independent correction factors to the
dosimeter response. Examples of type II dosimeters are given
NOTE 1—An expanded uncertainty derived by multiplying a combined
in Table 2.
standard uncertainty by a coverage factor of k=2 provides a level of
confidence of approximately 95 %. See ISO/ASTM 51707 and the GUM
6.3 Classification of Dosimetry Systems Based on the Field
for further details.
of Application:
6.3.2 Routine Dosimetry Systems —The classification of a
6.3.1 Reference Standard Dosimetry Systems:
6.3.1.1 The classification of a dosimetry system as a refer- dosimetry system as a routine dosimetry system is based on its
ence standard dosimetry system is based on its application. application, i.e. routine absorbed dose measurements, includ-
Reference standard dosimetry systems are used as standards to ing dose mapping and process monitoring.Aroutine dosimetry
calibrate the dosimetry systems that are used for routine system comprises dosimeters and the associated measurement
measurements. The uncertainty of the reference standard equipment and quality system documentation necessary to
dosimetry systemwillaffecttheuncertaintyofthesystembeing ensure traceability to appropriate national or international
calibrated and it is therefore important that the reference standards. The dosimeter used in a routine dosimetry system is
standard dosimetry system is of high metrological quality. In often a type II dosimeter, although type I dosimeters, such as
this context, the concept of high metrological quality implies a alanine, can also be used fo
...