ASTM E3083-17

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.
Designation: E3083 − 17
Standard Terminology Relating to
Radiation Processing: Dosimetry and Applications
This standard is issued under the fixed designation E3083; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This terminology covers terms that apply to radiation processing using ionizing radiation. The
common radiation fields considered are gamma radiation, X-radiation, and electrons. This treatment
is not intended to be exhaustive but reflects special and common terms used in technology and
applicationofinteresttoCommitteeE61,specifically,termsincludedintheE61setofISO/ASTMand
ASTM standards on radiation processing.
Thisterminologyusesrecommendeddefinitionsandconceptsofquantities,withunits,forradiation
measurements as contained in the International Commission on Radiation Units and Measurements
(ICRU) Report 85a on “Fundamental Quantities and Units for Ionizing Radiation,” October 2011.
Those terms that are defined essentially according to the terminology of ICRU Report 85a will be
followed by ICRU in parentheses. It should be noted that the units for quantities used are the latest
adoptedaccordingtotheInternationalSystemofUnits(SI).Thisterminologyalsousesrecommended
definitions of two JCGM documents, namely “International vocabulary of metrology” (VIM 2012)
and “Guide to the expression of uncertainty in measurement” (GUM, 2008). Those terms that are
defined essentially according to the terminology of these documents are followed by either VIM or
GUM in parentheses.As far as possible, it is also intended to harmonize the definitions with those in
Terminology E170, ISO 11139, and ISO 12749-4.
It is recommended that the use of the old units for quantities with special names be avoided;
however,ifitisdeemednecessarytousethemforclarity,valuesofquantitiesshouldbeexpressedfirst
in the new units followed by values in the old units in parentheses. Table X1.1 summarizes the
relationship between the old and new units for the quantities of interest.
Aterm is boldfaced when it is defined in this standard. For some terms, text in italics is used just
before the definition to limit its field of application, for example, see activity.
1. Scope the modification of polymers is referred to as radiation pro-
cessing. The types of radiation used may be gamma radiation
1.1 This terminology standard lists terms and definitions
(typically from cobalt-60 sources), X-radiation or accelerated
related to radiation processing concepts, especially radiation
electrons.
dose measurements. Use of this standard, and the common
terminology, will foster clearer communication, and remove
1.3 This standard provides terms and definitions for dosim-
ambiguity.
etry for radiation processing concepts dealing with procedures
related to operational qualification, performance qualification,
1.2 The use of ionizing radiation for the treatment of
and routine processing that may influence absorbed dose in the
commercial products such as the sterilization of medical
products, and types of dosimetry systems that may be used
devices, the reduction of microbial contamination in food or
during calibration or on a routine basis as part of quality
assurance in commercial radiation processing of products.
This terminology is under the jurisdiction of ASTM Committee E61 on
1.4 When selecting terms and definitions, special care has
Radiation Processing and is the direct responsibility of Subcommittee E61.01 on
Dosimetry. been taken to include the terms that need to be defined, that is
Current edition approved Oct. 1, 2017. Published November 2017. DOI:
to say, either because the definitions are essential to the correct
10.1520/E3083-17
understanding of the corresponding concepts or because some
Available from International Commission on Radiation Units and Measure-
specific ambiguities need to be addressed.
ments (ICRU), 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814.
Document produced by Working Groups of the Joint Committee for Guides in
1.5 The “Discussion” appended to certain definitions offers
Metrology (JCGM). Available free of charge at BIPM website (http://
www.bipm.org). clarification or examples to facilitate understanding of the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3083 − 17
conceptsdescribed.Incertaincases,miscellaneousinformation 3.2 Unambiguous communication of concepts is crucial
is also included, for example, the units in which a quantity is taking into account the relevant implications that may arise
normally measured, recommended parameter values, from misunderstandings with regard to equipment and materi-
references, etc. alsinvolvedinthestandardsdealingwithanysubjectregarding
radiation processing activities. Concepts dealing with dosim-
1.6 This standard does not purport to address all of the
etry related to radiation processing and procedures for
safety concerns, if any, associated with its use. It is the
preparation, testing, and using dosimetry systems to determine
responsibility of the user of this standard to establish appro-
the absorbed dose are present in all standards developed by
priate safety, health, and environmental practices and deter-
E61 and ISO/TC85/WG3 and need to be designated by
mine the applicability of regulatory limitations prior to use.
common terms and described by harmonized definitions in
1.7 This international standard was developed in accor-
order to avoid misunderstandings.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4. Terminology
Development of International Standards, Guides and Recom-
4.1 Terms and Definitions:
mendations issued by the World Trade Organization Technical
absorbed dose (D)—quotient of dɛ¯bydm, where dɛ¯ is the
Barriers to Trade (TBT) Committee.
mean energy imparted by ionizing radiation to matter of
mass dm (ICRU), thus
2. Referenced Documents
¯
2.1 ASTM Standards:
D 5 dϵ⁄dm
DISCUSSION—The SI unit of absorbed dose is the gray (Gy), where 1
E170Terminology Relating to Radiation Measurements and
gray is equivalent to the absorption of 1 joule per kilogram of the
Dosimetry
specified material (1 Gy=1 J/kg).
2.2 ISO/ASTM Standards:
˙
absorbed-dose rate (D)—quotient of dD by dt, where dD is
ISO/ASTM 51649Practice for Dosimetry in an Electron
the increment of absorbed dose in the time interval dt
Beam Facility for Radiation Processing at Energies Be-
(ICRU), thus
tween 300 keV and 25 MeV
˙
2.3 Joint Committee for Guides in Metrology (JCGM)
D 5 dD⁄dt
Reports: DISCUSSION—
-1
(1) The SI unit is Gy·s . However, the absorbed-dose rate is often
JCGM100:2008,GUM1995,withminorcorrectionsEvalu-
specified in terms of its average value over longer time intervals, for
ation of measurement data – Guide to the expression of
-1 -1
example, in units of Gy·min or Gy·h .
uncertainty in measurement
(2) In gamma industrial irradiators, dose rate may be significantly
JCGM 200:2012, VIMInternational vocabulary of metrol-
different at different locations where product is irradiated.
ogy – Basic and general concepts and associated terms
(3) In electron-beam irradiators with pulsed or scanned beam, there are
two types of dose rate: average value over several pulses (scans) and
2.4 ICRU and BIPM Documents:
instantaneous value within a pulse (scan). These two values can be
ICRU 85aFundamental quantities and units for ionizing
significantly different.
radiation
BIPMThe International System of Units (SI)
absorbed-dose mapping—measurement of absorbed dose
within an irradiated product to produce a one-, two-, or
2.5 ISO Standards:
three-dimensional distribution map of absorbed dose.
12749-4Nuclear energy, nuclear technologies, and radio-
DISCUSSION—For a process load, such a dose map is obtained using
logical protection – Vocabulary – Part 4: Dosimetry for
dosimeters placed at specified locations within the process load.
radiation processing
ISO/TS 11139Sterilization of health care products – Vo- accredited dosimetry calibration laboratory—dosimetry
cabulary laboratory with formal recognition by an accrediting orga-
ISO/IEC 17025General requirements for the competence of nization that the dosimetry laboratory is competent to carry
testing and calibration laboratories out specific activities which lead to calibration or calibra-
tion verification of dosimetry systems in accordance with
3. Significance and Use
documented requirements of the accrediting organization.
3.1 The purpose of this standard is to facilitate communi-
activity (A)—of an amount of radionuclide in a particular
cation and promote common understanding within the profes-
energy state at a given time,quotientof–dNbydt,wheredN
sionals in radiation processing research and industry.
is the mean change in the number of nuclei in that energy
state due to spontaneous nuclear transitions in the time
interval dt (ICRU), thus
For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
A52dN⁄dt
www.astm.org, or contact ASTM Customer Service at service@astm.org. For -1
Unit: s
Annual Book of ASTM Standards volume information, refer to the standard’s
The special name for the unit of activity is becquerel (Bq),
Document Summary page on the ASTM website.
-1
5 thus1Bq=1s .
Available in electronic form at www.bipm.org/en/si/si_brochure/
DISCUSSION—
Available from International Organization for Standardization (ISO), ISO
(1) The former special unit of activity was the curie (Ci).
Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
10 -1
Geneva, Switzerland, http://www.iso.org. 1 Ci=3.7 × 10 s .
E3083 − 17
(2)The‘particularenergystate’isthegroundstateofthenuclideunless electron to deviate from its original motion. This interaction results in
otherwise specified. a loss of kinetic energy by the emission of electromagnetic radiation.
(3) The activity of an amount of radionuclide in a particular energy Since such encounters are uncontrolled, they produce a continuous
state is equal to the product of the decay constant, λ, for that state and photon energy distribution that extends up to the maximum kinetic
the number of nuclei in that state (that is A=Nλ). energy of the incident electron.
(2) The bremsstrahlung spectrum depends on the electron energy, the
alanine dosimeter—specified quantity and physical form of
composition and thickness of the target, and the angle of emission with
the radiation-sensitive material alanine and any added inert
respect to the incident electron.
substance such as a binder.
calibration—set of operations that establish, under specified
analysis wavelength—wavelength used in a spectrophotomet- conditions, the relationship between values of quantities
ric instrument for the measurement of optical absorbance or indicatedbyameasuringinstrumentormeasuringsystem,or
reflectance. values represented by a material measure or a reference
material,andthecorrespondingvaluesrealizedbystandards.
approved laboratory—laboratory that is a recognized na-
DISCUSSION—Calibration conditions include environmental and irra-
tionalmetrologyinstitute,orhasbeenformallyaccreditedto
diation conditions present during irradiation, storage and measurement
ISO/IEC 17025, or has a quality system consistent with the
of the dosimeters that are used for the generation of a calibration
requirements of ISO/IEC 17025. curve.
DISCUSSION— calibration curve—expression of the relation between indica-
(1) A recognized national metrology institute or other calibration
tion and corresponding measured quantity value (VIM).
laboratory accredited to ISO/IEC 17025 should be used in order to
DISCUSSION—In radiation processing standards, the term ‘dosimeter
ensure traceability to a national or international standard.
response’ is generally used for ‘indication’.
(2)Acalibration certificate provided by a laboratory not having formal
recognitionoraccreditationwillnotnecessarilybeproofoftraceability calorimeter—assembly consisting of calorimetric body
to a national or international standard.
(absorber), thermal insulation, and temperature sensor with
wiring.
beam length—dimension of the irradiation zone along the
direction of product movement, at a specified distance from
cellulose triacetate dosimeter—–piece of CTA film that,
the accelerator window.
during exposure to ionizing radiation, exhibits a quantifiable
DISCUSSION—
change in specific net absorbance as a function of ab-
(1) For graphic illustration, see ISO/ASTM 51649.
sorbed dose.
(2) This term usually applies to electron irradiation.
(3) Beam length is therefore perpendicular to beam width and to the
ceric-cerous dosimeter—specially prepared solution of ceric
electron beam axis.
sulfateandceroussulfateinsulfuricacid,individuallysealed
(4)Incaseofproductthatisstationaryduringirradiation,‘beamlength’
in an appropriate container such as a glass ampoule, where
and ‘beam width’ may be interchangeable.
the radiation-induced changes in electropotential or optical
beam width—dimension of the irradiation zone perpendicular absorbance of the solution is related to absorbed dose to
to the direction of product movement, at a specified distance water.
from the accelerator window.
charged-particle equilibrium (referred to as electron equilib-
DISCUSSION—
rium in the case of electrons set in motion by photon
(1) For graphic illustration, see ISO/ASTM 51649.
irradiation of a material)–—condition in which the kinetic
(2) This term usually applies to electron irradiation.
(3) Beam width is therefore perpendicular to beam length and to the energy of charged particles (or electrons), excluding rest
electron beam axis.
mass, entering an infinitesimal volume of the irradiated
(4) In the case of product that is stationary during irradiation, ‘beam
material equals the kinetic energy of charged particles (or
width’ and ‘beam length’ may be interchangeable.
electrons) emerging from it.
(5) Beam width may be quantified as the distance between two points
along the dose profile, which are at a defined fraction of the maximum
combined standard measurement uncertainty–—standard
dose value in the profile.
measurement uncertainty that is obtained using the indi-
(6) Various techniques may be employed to produce an electron beam
vidual standard measurement uncertainties associated with
width adequate to cover the processing zone; for example, use of
the input quantities in a measurement model (VIM).
electromagnetic scanning of a pencil beam (in which case beam width
DISCUSSION—
is also referred to as scan width), defocusing elements, and scattering
(1) It is also referred to as ‘combined standard uncertainty.’
foils.
(2) In case of correlations of input quantities in a measurement model,
bremsstrahlung—broad-spectrum electromagnetic radiation
covariances must also be taken into account when calculating the
combined standard measurement uncertainty.
emitted when an energetic charged particle is influenced by
astrongelectricormagneticfield,suchasthatinthevicinity
compensating dummy—see simulated product.
of an atomic nucleus.
coverage factor (k)—number larger than one by which a
DISCUSSION—
combined standard measurement uncertainty is multi-
(1) In radiation processing, bremmstrahlung photons with sufficient
plied to obtain an expanded measurement uncertainty-
energy to cause ionization are generated by the deceleration or
(VIM).
deflection of energetic electrons in a target material. When an electron
passes close to an atomic nucleus, the strong coulomb filed causes the DISCUSSION—Acoverage factor, k, is typically in the range of 2 to 3.
E3083 − 17
DISCUSSION—
decay constant (λ)—of a radionuclide in a particular energy
(1)Electronvolt(eV)isoftenusedastheunitforelectronbeamenergy
state, quotient of –dN/N by dt, where dN/N is the mean
-19
where 1 eV = 1.602·10 J.
fractionalchangeinthenumberofnucleiinthatenergystate
(2) In radiation processing, where beams with a broad electron energy
due to spontaneous nuclear transformations in the time
spectrum are frequently used, the terms most probable energy (E ) and
p
interval dt (ICRU), thus
average energy (E ) are common. They are linked to the practical
a
electron beam range (R ) and half-value depth (R ) by empirical
2dN⁄N p 50
λ 5
equations.
dt
-1
Unit: s
electron energy spectrum—particle fluence distribution of
DISCUSSION—The quantity (ln 2)/λ is commonly called the half-life,
electrons as a function of energy.
T ⁄2 , of the radionuclide; that is, the time taken for the activity of an
amount of radionuclide to become half its initial value.
electron equilibrium—charged-particle equilibrium for
electrons.
depth-dose distribution—variation of absorbed dose with
depth from the incident surface of a material exposed to a
ethanol-chlorobenzene dosimeter—partly deoxygenated so-
given radiation.
lution of chlorobenzene (CB) in 96 volume % ethanol in an
appropriate container, such as a flame-sealed glass ampoule,
dichromate dosimeter—solutioncontainingsilveranddichro-
used to indicate absorbed dose by measurement of the
mate ions in perchloric acid in an appropriate container such
amount of HC1 formed under radiation.
as a sealed glass ampoule that indicates absorbed dose by
change (decrease) in absorbance at a specified wavelength.
expanded uncertainty—quantity defining an interval about
dose uniformity ratio—ratioofthemaximumtotheminimum the result of a measurement that may be expected to
absorbed dose within the irradiated product. encompass a large fraction of the distribution of values that
DISCUSSION—The concept is also referred to as the max/min dose could reasonably be attributed to the measurand (GUM).
ratio.
DISCUSSION—
(1) Expanded uncertainty is obtained by multiplying the combined
dosimeter—device that, when irradiated, exhibits a quantifi-
standard measurement uncertainty by a coverage factor, the value
able change that can be related to absorbed dose in a given
of which determines the magnitude of the ‘fraction’.
material using appropriate measurement instruments and
(2) Expanded uncertainty is also referred to as ‘overall uncertainty’.
procedures.
Fricke dosimeter—air-saturated solution of ferrous sulfate or
dosimeter batch—quantity of dosimeters made from a spe-
ferrous ammonium sulfate that indicates absorbed dose by
cific mass of material with uniform composition, fabricated
an increase in optical absorbance at a specified wavelength.
in a single production run under controlled, consistent
good manufacturing practice (GMP)—procedures estab-
conditions, and having a unique identification code.
lished and exercised throughout the production,
dosimeter response—reproducible, quantifiable change pro-
manufacturing, processing, packing, and distribution of
duced in the dosimeter by ionizing radiation.
foods, encompassing maintenance of sanitation systems,
DISCUSSION—
quality control and quality assurance, qualification of
(1) The dosimeter response value, obtained from one or more
personnelandotherrelevantactivities,toensurethedelivery
measurements, is used in the estimation of the absorbed dose.
of a commercially acceptable and safe product.
(2) The response value may be obtained from such measurements as
optical absorbance, peak-to-peak distance in EPR spectra, or electro-
influence quantity—quantity that, in a direct measurement,
potential between solutions.
does not affect the quantity that is actually measured, but
dosimeter/dosimetry system characterization—
affects the relation between the indication and the measure-
determination of performance characteristics, such as useful
ment result (VIM).
dose range, reproducibility, and the effects of influence
DISCUSSION—In radiation processing dosimetry, this term includes
quantities, for a dosimeter/dosimetry system under defined temperature, relative humidity, time intervals, light, radiation energy,
absorbed-dose rate, and other factors that might affect dosimeter
test conditions.
response, as well as quantities associated with the measurement
dosimeter set—one or more dosimeters used to measure
instrument.
absorbed dose at a location and whose average response is
in-situ/in-plant calibration—calibration where the dosim-
used to determine absorbed dose at that location.
eterirradiationisperformedintheplaceofuseoftheroutine
dosimetry—measurement of absorbed dose by the use of a
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