ISO/ASTM 51205:2009

Practice for use of a ceric-cerous sulfate dosimetry system

ISO 51205:2009 applies to the procedures for preparation, testing, and using the ceric-cerous sulfate dosimetry system to determine absorbed dose (in terms of absorbed dose to water) in materials irradiated by photons (gamma radiation or X-radiation/bremsstrahlung) or high-energy electrons. The system consists of a dosimeter and appropriate analytical instrumentation. The system is classified as a reference–standard dosimetry system but can also be used as a transfer–standard dosimeter or a routine dosimeter.

Pratique de l'utilisation d'un système dosimétrique au sulfate cérique-céreux

General Information

• Status: Withdrawn
• Publication Date: 06-Jul-2009
• Withdrawal Date: 06-Jul-2009
• ICS: 17.240 - Radiation measurements
• Technical Committee: ISO/TC 85 - Nuclear energy, nuclear technologies, and radiological protection
• Drafting Committee: ISO/TC 85 - Nuclear energy, nuclear technologies, and radiological protection
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 03-May-2017

Relations

• Revised: ISO/ASTM 51205:2017 - Practice for use of a ceric-cerous sulfate dosimetry system
• Effective Date: 28-May-2016
• Revises: ISO/ASTM 51205:2002 - Practice for use of a ceric-cerous sulfate dosimetry system
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO/ASTM
STANDARD 51205
Second edition
2009-06-15
Practice for use of a ceric-cerous sulfate
dosimetry system
Pratique de l’utilisation d’un système dosimétrique au sulfate
cérique-céreux
Reference number
ISO/ASTM 51205:2009(E)
© ISO/ASTM International 2009

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ISO/ASTM51205:2009(E)
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ii © ISO/ASTM International 2009 – All rights reserved

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ISO/ASTM51205:2009(E)
Contents Page
1 Scope . 1
2 Referenced documents . 1
3 Terminology . 2
4 Significance and use . 2
5 Interferences . 3
6 Apparatus . 3
7 Reagents . 3
8 Preparation of the dosimeters . 3
9 Analytical instrument performance . 4
10 Calibration of the dosimetry system . 4
11 Application of dosimetry system . 6
12 Minimum documentation requirements . 6
13 Measurement uncertainty . 7
14 Keywords . 7
Annexes . 7
Bibliography . 11
Figure A1.1 Electrochemical cell . 8
© ISO/ASTM International 2009 – All rights reserved iii

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ISO/ASTM51205:2009(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.
Draft International Standards adopted by the technical committees are circulated to the member bodies for
voting. Publication as an International Standard requires approval by at least 75% of the member bodies
casting a vote.
ASTM International is one of the world’s largest voluntary standards development organizations with global
participation from affected stakeholders. ASTM technical committees follow rigorous due process balloting
procedures.
A pilot project between ISO and ASTM International has been formed to develop and maintain a group of
ISO/ASTM radiation processing dosimetry standards. Under this pilot project, ASTM Subcommittee E10.01,
Radiation Processing: Dosimetry and Applications, is responsible for the development and maintenance of
these dosimetry standards with unrestricted participation and input from appropriate ISO member bodies.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. Neither ISO nor ASTM International shall be held responsible for identifying any or all such patent
rights.
International Standard ISO/ASTM 51205 was developed by ASTM Committee E10, Nuclear Technology and
Applications, through Subcommittee E10.01, and by Technical Committee ISO/TC 85, Nuclear energy.
This second edition cancels and replaces the first edition (ISO/ASTM 51205:2002), which has been technically
revised.
iv © ISO/ASTM International 2009 – All rights reserved

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ISO/ASTM 51205:2009(E)
Standard Practice for
1
Use of a Ceric-Cerous Sulfate Dosimetry System
This standard is issued under the fixed designation ISO/ASTM 51205; 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 1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This practice covers the procedures for preparation,
responsibility of the user of this standard to establish appro-
testing, and using the ceric-cerous sulfate dosimetry system to
priate safety and health practices and determine the applica-
determine absorbed dose (in terms of absorbed dose to water)
bility of regulatory limitations prior to use.
in materials irradiated by photons (gamma radiation or
X-radiation/bremsstrahlung)orhigh-energyelectrons.Thesys-
2. Referenced documents
tem consists of a dosimeter and appropriate analytical instru-
3
2.1 ASTM Standards:
mentation. For simplicity, the system will be referred to as the
C912 Practice for Designing a Process for Cleaning Tech-
ceric-cerous system. It is classified as a reference–standard
nical Glasses
dosimetrysystem(seeISO/ASTMGuide51261).Ceric-cerous
E170 Terminology Relating to Radiation Measurements
dosimeters are also used as transfer–standard dosimeters or
and Dosimetry
routine dosimeters.
E178 Practice for Dealing With Outlying Observations
1.2 This practice describes both the spectrophotometric and
E275 Practice for Describing and Measuring Performance
the potentiometric readout procedures for the ceric-cerous
of Ultraviolet and Visible Spectrophotometers
system.
E 666 Practice for Calculating Absorbed Dose From
1.3 This practice applies provided the following conditions
Gamma or X Radiation
are satisfied:.
E668 Practice for Application of Thermoluminescence-
1.3.1 The absorbed-dose range is between 0.5 and 50 kGy
2 Dosimetry(TLD)SystemsforDeterminingAbsorbedDose
(1).
6 −1
in Radiation-Hardness Testing of Electronic Devices
1.3.2 The absorbed-dose rate is less than 10 Gy s (1).
E 925 Practice for Monitoring the Calibration of
1.3.3 For radionuclide gamma-ray sources, the initial pho-
Ultraviolet-Visible Spectrophotometers whose Spectral
ton energy is greater than 0.6 MeV. For bremsstrahlung
Slit Width does not Exceed 2 nm
photons, the energy of the electrons used to produce the
E958 Practice for Measuring Practical Spectral Bandwidth
bremsstrahlung photons is equal to or greater than 2 MeV. For
of Ultraviolet-Visible Spectrophotometers
electron beams, the initial electron energy is greater than 8
3
2.2 ISO/ASTM Standards:
MeV.
51261 Guide for Selection and Calibration of Dosimetry
NOTE 1—The lower energy limits are appropriate for a cylindrical
Systems for Radiation Processing
dosimeter ampoule of 12-mm diameter. Corrections for dose gradients
51400 Practice for Characterization and Performance of a
acrossanampouleofthatdiameterorlessarenotrequiredforphotons,but
High-Dose Radiation Dosimetry Calibration Laboratory
may be required for electron beams (2). The ceric-cerous system may be
51707 Guide for Estimating Uncertainties in Dosimetry for
used at lower energies by employing thinner (in the beam direction)
Radiation Processing
dosimeters.
2.3 International Commission on Radiation Units and
1.3.4 The irradiation temperature of the dosimeter is above
4
Measurements (ICRU) Reports:
0°C and below 62°C (3).
ICRU Report 14 Radiation Dosimetry: X-Rays and Gamma
NOTE 2—The temperature dependence of dosimeter response is known
RayswithMaximumPhotonEnergiesBetween0.6and60
only in this range (see 4.3). Use outside this range requires determination
MeV
of the temperature dependence.
ICRU Report 34 The Dosimetry of Pulsed Radiation
ICRU Report 35 Radiation Dosimetry: Electrons with
Initial Energies Between 1 and 50 MeV
1
This guide is under the jurisdiction of ASTM Committee E10 on Nuclear
ICRU Report 37 Stopping Powers for Electrons and
Technology and Applications and is the direct responsibility of Subcommittee
Positrons
E10.01 on Radiation Processing: Dosimetry andApplications, and is also under the
jurisdiction of ISO/TC 85/WG 3.
Current edition approved June 18, 2008. Published June 2009. Originally
3
published asASTM E 1205–88. Last previousASTM edition E 1205–99.ASTM E For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
1205–93 was adopted by ISO in 1998 with the intermediate designation ISO www.astm.org, or contact ASTM Customer Service at [e-mail]. For
15555:1998(E). The present International Standard ISO/ASTM 51205:2009(E) is a Annual Book of ASTM Standards volume information, refer to the standard’s
major revision of ISO/ASTM 51205-2002(E) which replaced ISO 15555. Document Summary page on the ASTM website.
2 4
Theboldfacenumbersinparenthesesrefertothebibliographyattheendofthis Available from International Commission on Radiation Units and Measure-
standard. ments, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814, USA.
© ISO/ASTM International 2009 – All rights reserved
1

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ISO/ASTM51205:2009(E)
ICRU Report 60 Radiation Quantities and Units for Ioniz- 3.1.9 response function—mathematical representation of
ing Radiation the relationship between dosimeter response and absorbed
dose, for a given dosimetry system.
3. Terminology
3.1.10 routine dosimeter—dosimeter calibrated against a
primary–, reference–, or transfer–standard dosimeter and used
3.1 Definitions:
for routine absorbed-dose measurements.
3.1.1 calibration—set of operations under specified condi-
tions, which establishes the relationship between values indi- 3.1.11 transfer–standard dosimeter—a dosimeter, often a
reference–standard dosimeter suitable for transport between
cated by a measuring instrument or measuring system, and the
corresponding values realized by standards traceable to a different locations, used to compare absorbed-dose measure-
nationally or internationally recognized laboratory. ments.
3.1.1.1 Discussion—Calibration conditions include envi-
3.2 Definitions of Terms Specific to This Standard:
ronmentalandirradiationconditionspresentduringirradiation,
3.2.1 electropotential, E—difference in potential between
storageandmeasurementofthedosimetersthatareusedforthe
the solutions in the two compartments of an electrochemical
generation of a calibration curve. To achieve stable environ-
cell, measured in millivolts.
mental conditions, it may be necessary to condition the
3.3 For definitions of other terms used in this practice that
dosimeters before performing the calibration procedure.
pertain to radiation measurement and dosimetry, refer to
3.1.2 calibration curve—graphical representation of the
ASTMTerminology E170. Definitions inASTMTerminology
dosimetry system’s response function.
E170 are compatible with ICRU 60; that document, therefore,
3.1.3 ceric-cerous dosimeter—specially prepared solution
may be used as an alternative reference.
of ceric sulfate and cerous sulfate in sulfuric acid, individually
sealed in an appropriate container such as a glass ampoule,
4. Significance and use
where the radiation-induced changes in electropotential or
4.1 The ceric-cerous system provides a reliable means for
optical absorbance of the solution are related to absorbed dose
determining absorbed dose to water. It is based on a process of
to water.
reductionofcericionstocerousionsinacidicaqueoussolution
3.1.4 measurement quality assurance plan—documented
by ionizing radiation (1, 4).
program for the measurement process that ensures that the
expanded uncertainty consistently meets the requirements of
NOTE 3—The ceric-cerous system described in the practice has cerous
the specific application. This plan requires traceability to
sulfate added to the initial solution to reduce the effect of organic
nationally or internationally recognized standards.
impurities and to allow the potentiometric method of measurement. Other
3.1.5 molar linear absorption coeffıcient, ´ —constant re- systems used for dosimetry include solutions of ceric sulfate or ceric
m
ammonium sulfate in sulfuric acid without the initial addition of cerous
lating the spectrophotometric absorbance, A , of an optically
l
sulfate.Theseothersystemsarebasedonthesameprocessofreductionof
absorbing molecular species at a given wavelength, l, per unit
ceric ions to cerous ions but are not included in this practice.
pathlength, d, to the molar concentration, c, of that species in
solution:
4.2 The dosimeter is a solution of ceric sulfate and cerous
sulfate in sulfuric acid in an appropriate container such as a
A
l
´ 5 (1)
m
d· c flame-sealed glass ampoule. The solution indicates a level of
absorbed dose by a change (decrease) in optical absorbance at
2 −1
SI unit: m mol
a specified wavelength in the ultraviolet region, or a change
3.1.5.1 Discussion—The measurement is sometimes ex-
(increase)inelectropotential.Acalibratedspectrophotometeris
−1 −1
pressed in units of L mol cm .
used to determine the absorbance and a potentiometer, with a
3.1.6 net absorbance, DA—change in measured optical
specially designed cell, is used to determine the electropoten-
absorbanceataselectedwavelengthdeterminedastheabsolute
tial in millivolts.
difference between the pre-irradiation absorbance, A , and the
o
4.3 The dosimeter response has an irradiation temperature
post-irradiation absorbance, A, as follows:
31
dependence since the radiation chemical yield ( G~Ce ! )
DA 5|A2A | (2)
o 31
depends on temperature. The dependence of G~Ce ! is ap-
3.1.7 radiationchemicalyield,G(x)—quotientofn(x)by ´¯,
proximately equal to −0.2% per degree Celsius between 0 and
where n(x) is the mean amount of a specified entity, x,
62°C (3, 5, 6). This irradiation temperature dependence has a
produced, destroyed, or changed by the mean energy, ´¯,
slight dependence on the initial cerous ion concentration (see
imparted to the matter.
10.6.3).
n~x! 4.4 The absorbed dose to materials other than water when
G~x! 5 (3)
´¯
irradiated under equivalent conditions may be calculated.
−1
Procedures for making such calculations are given in ASTM
SI unit: mol J
Practices E666 and E668 and ISO/ASTM Guide 51261.
3.1.8 reference–standard dosimeter—dosimeter of high
metrological quality used as a standard to provide measure-
NOTE 4—For a comprehensive discussion of various dosimetry meth-
mentstraceabletomeasurementsmadeusingprimary–standard
ods applicable to the radiation types and energies discussed in this
dosimeters. practice, see ICRU Reports 14, 34, 35, and 37.
© ISO/ASTM International 2009 – All rights reserved
2

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ISO/ASTM51205:2009(E)
results without requiring additional cleaning.
5. Interferences
5.1 The ceric-cerous dosimetric solution response is sensi-
7. Reagents
tivetoimpurities,particularlyorganicimpurities.Evenintrace
7.1 Analytical reagent grade chemicals shall be used for
quantities, impurities can cause a detectable change in the
5
preparing all solutions.
observed response (7). Organic materials shall not be used for
7.2 Water quality is very important since it is the major
any component in contact with the solution unless they have
component of the dosimetric solutions, and therefore may be
been tested and shown to have no effect. The effect of trace
the prime source of contamination. The water quality is more
impurities is minimized by the addition of cerous ions to the
important for ceric-cerous dosimeters used for measurements
solution (8, 9). Water purification methods found to be ad-
in the lower absorbed-dose range than for those used in the
equate for use in preparing ceric-cerous dosimeters are de-
upper absorbed-dose range. For high-range dosimeters double-
cribed in 7.2.
distilled water from coupled all-glass and silica stills can be
5.2 Undesirablechemicalchangesinthedosimetricsolution
used. For low-range dosimeters, use triply-distilled water.
can occur if care is not taken during sealing of the ampoules
Alternatively, use water from a high-quality commercial puri-
(see 8.7).
fication unit capable of achieving Total Oxidizable Carbon
(T.O.C.) content below 5 ppb. Use of deionized water is not
6. Apparatus
recommended.
6.1 Spectrophotometric Method—For the analysis of the
NOTE 7—Double-distilled water distilled from an alkaline potassium
dosimetric solution, use a high-precision spectrophotometer
permanganate (KMnO ) solution (2 g KMnO plus 5 g sodium hydroxide
4 4
capable of measuring absorbance values up to two with an
(NaOH)pelletsin2Lofdistilledwater)hasbeenfoundtobeadequatefor
uncertainty of no more than 1% in the region from 254 to 320
routine preparation of the dosimetric solution. High-purity water is
nm. Use quartz cuvettes with 10-mm path length for spectro-
commercially available from some suppliers. Such water labeled HPLC
photometric measurements of absorbance of the solution. (high-pressure liquid chromatographic) grade is usually sufficiently free
from organics to be used in this practice.
6.2 Potentiometric Method—Use an electrochemical cell,
similar to that described inAnnexA1 (see Fig.A1.1). Measure
7.3 Do not store purified water used in this practice in
theelectropotentialacrossthecellwithahigh-precisiondigital
plastic containers or in containers with plastic caps or plastic
potentiometer that is capable of measuring dc potentials in the
cap liners.
range from 1 to 100 mV within an uncertainty of 1%.
8. Preparation of the dosimeters
NOTE 5—As shown in Fig. A1.1, the electrochemical cell has two
8.1 The recommended concentrations for the ceric-cerous
compartments separated by a porous junction, such as a glass frit, a
dosimeter to measure absorbed doses from about 5 to 50 kGy
ceramicorkaolinjunction,orafibreglasswick.Theinnercompartmentis
−3
(high-range dosimeter) are 15 mmol dm ceric sulfate
filled with unirradiated solution. The lower compartment is filled with
−3
solution transferred from an irradiated or unirradiated ampoule. The
[Ce(SO ) ·4H O] and 15 mmol dm cerous sulfate
4 2 2
electropotential, E, generated between the platinum electrodes in the two
[Ce (SO ) ·8H O]. For measurement of absorbed doses from
2 4 3 2
compartments is measured by a digital potentiometer.
about 0.5 to 10 kGy (low-range dosimeter), the recommended
−3
concentrations are 3 mmol dm [Ce(SO ) ·4H O] and 3
6.3 Glassware—Useborosilicateglassorequivalentchemi-
4 2 2
−3
mmol dm [Ce (SO ) ·8H O].
cally resistant glass to store the reagents and the prepared
2 4 3 2
8.2 The dosimetric solutions specified in 8.1 may be formu-
dosimetric solution. Clean all glassware, except ampoules,
lated from the following nominal stock solutions: (a) 0.4 mol
using chromic acid cleaning solution or an equivalent cleaning
−3 −3 −3
dm and 4 mol dm sulfuric acid (H SO ), (b) 0.1 mol dm
agent (see ASTM Practice C912). Rinse at least three times
2 4
−3
with double-distilled water. Dry thoroughly and store under Ce(SO ) ·4H O, and (c) 0.1 mol dm Ce (SO ) ·8H O.
4 2 2 2 4 3 2
Procedures for preparing these solutions are given in Annex
conditions that will minimize exposure to dust.
A2. (Warning—Concentrated sulfuric acid is corrosive and
6.4 Glass Ampoules—If required, clean glass ampoules in
can cause serious burns. Ceric-cerous solutions are skin irri-
boiling double-distilled water. Rinse twice with double-
tants.Appropriate precautions should be exercised in handling
distilled water and oven dry.
these materials.)
NOTE 6—The dosimetric ampoule normally used has a capacity of
approximately 2 mL. Quick-break glass ampoules, or Type 1 glass
5
colorbreak ampoules or equivalent containers, are commonly used.
Reagent specifications are available from American Chemical Society, 1115
th
Commercially available ampoules have been found to give reproducible 16 St., Northwest, Washington, DC 20036, USA.
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ISO/ASTM51205:2009(E)
8.3 Use the following equations to determine the volume in filling ampoules to avoid depositing solution in the ampoule
millilitres of each stock solution necessary to prepare 1 L of neck. Subsequent heating during sealing may cause an unde-
dosimetric solution: sirable chemical change in the dosimetric solution remaining
inside the ampoule neck. Flame seal the ampoules, exercising
High Range Low Range
care to avoid heating the body of the ampoule during sealing.
V 0.015 V 0.003
1 1
5 5 (4) 8.8 Storedosimetersinadarkplaceatroomtemperature(23
1000 c 1000 c
1 1
6 5°C).
V 0.015 V 0.003
2 2
5 5 (5)
1000 c 1000 c
2 2
9. Analytical instrument performance
V 0.4 V 0.4 9.1 Spectrophotometer Performance:
3 3
5 5 (6)
1000 2 V c 1000 2 V c
1 3 1 3
9.1.1 Check the wavelength scale of the spectrophotometer.
Appropriate wavelength standards are holmium-oxide filters
V 5 1000 2 V 2 V 2 V V 5 1000 2 V 2 V 2 V (7)
4 1 2 3 4 1 2 3
and solutions. For more details see ASTM Practices E275,
E925, and E958.
where:
−3
V = volume of nominal 0.1 mol dm ceric-sulfate stock NOTE 9—For example, holmium-oxide solutions in sealed cuvettes are
1
available as certified wavelength standards (SRM 2034) for use in the
solution,
−3
wavelength region from 240 to 650 nm (10).
V = volumeofnominal0.1moldm cerous-sulfatestock
2
solution,
9.1.2 Check the accuracy of the photometric (absorbance)
−3
V = volume of nominal 4 mol dm sulfuric-acid stock
3 scale of the spectrophotometer. Certified absorbance standard
solution,
filters or solutions are available for this purpose.
V = volume of distilled water,
4
NOTE 10—Examples of absorbance standards are solutions of various
c = actual concentration of the ceric-sulfate stock solu-
1
concentrations, such as SRM 931d (11) and SRM 935 (12), and metal-
tion,
on-quartz filters, such as SRM 2031 (13, 14).
c = actual concentration of the cerous-sulfate stock solu-
2
9.1.3 Check the linearity of the absorbance scale of the
tion, and
−3
c = actual concentration of the nominal 4 mol dm spectrophotometer as a function of the ceric-ion concentration.
3
Thisshouldbedoneatthepeakoftheabsorbancespectrumfor
sulfuric-acid stock solution.
the ceric ion at 320 nm at a constant temperature, preferably
−3
NOTE 8—If the nominal concentrations of c = c = 0.1 mol dm , and
1 2
25°C. The standardized ceric-sulfate stock solution (0.1 mol
−3
c =4moldm areassumed,thenV =V =150mLforthehighrangeand
−3 −3
3 1 2
dm nominal in 0.4 mol dm H SO ), as described in A2.3,
2 4
V = V = 30 mLfor the low range; V = 85 mLfor the high range and V =
1 2 3 3
may be used for this measurement. The plot of measured
97 mL for the low range. If the concentrations of the various stock
absorbance, A, per unit path length versus concentration shall
solutions are significantly different from the nominal values, then use Eq
4-6todeterminetheexactvolumes.Toprepareavolumeofthedosimetric be linear. The slope of the line gives, ´ , the molar linear
m
solution other than 1000 mL, the result of these equations should be
absorption coefficient.
multiplied by the ratio of the desired volume in millilitres to 1000 mL.
2 −1
NOTE 11—Areferencevaluefor ´ is561m ·mol 60.4%at320nm
m
8.4 Determine all of the volumes given in 8.3 using a
(3).
calibrated graduated cylinder that can be read to within 60.5
9.2 Potentiometer and Electrochemical Cell Performance:
mL.
9.2.1 For the potentiometer method, correct performance
8.5 Transfer the volume of each component of the dosim-
can be demonstrated by showing that the readings of dosim-
etricsolutionintoa1-Lorlargerglassstoragecontainer.Rinse
eters given known absorbed doses are in agreement with the
the graduated cylinder used for measuring V , V , and V by
1 2 3
expected readings within the limits of the dosimetry system
using some portion of the distilled water of V . Stopper the
4 uncertainty (see Section 13).
container and shake well. Before use, allow the dosimetric
NOTE 12—This method is only applicable for reference-standard do-
solution to stand for at least five days in the dark.
simetry systems where the long-term stability of the response has been
8.6 Qualitycontroltestingofthedosimetricsolutionpriorto
demonstrated and documented.
ampouling is performed by comparing the measurement of
10. Calibration of the dosimetry system
dosimetric solution parameters, such as ceric-ion concentra-
tion, cerous-ion concentration, ceric-ion molar linear absorp-
10.1 The dosimetry system shall be calibrated prior to use
tioncoefficient,radiationchemicalyieldforthecerousion,and
and at intervals thereafter in accordance with the user’s
density with acceptable values. Procedures for performing
documented procedure that specifies details of the calibration
these measurements are given in Annex A3. Quality control
process and quality assurance requirements. Calibration re-
testing following ampouling is performed by comparing cali-
quirements are given in ISO/ASTM Guide 51261.
bration data for the new dosimeter batch with data obtained
10.2 CalibrationIrradiationofDosimeters—Irradiationisa
from previous batches (see 10.5.3).
critical component of the calibration of the dosimetry system.
8.7 Prepare dosimeters by filling ampoules with approxi- Calibration irradiations shall be performed at a national or
mately 2 mLof dosimetric solution. Take care not to contami- accredited laboratory using criteria specified in ISO/ASTM
nate the dosimetric solution with impurities. Exercise care in Practice 51400.
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ISO/ASTM51205:2009(E)
10.2.1 Specify the dose in terms of absorbed dose to water. 10.5.4 If the cell is not going to be used for more than three
10.2.2 When the ceric-cerous dosimeter is used as a routine days, drain all solution from the cell. Rinse both the inner and
dosimeter, the calibration irradiation may be performed by outer compartments three times with distilled water, and allow
irradiating the dosimeters at (a) a national or accredited thecelltoairdry.Referto10.5.1and10.5.2beforereusingthe
laboratory using criteria specified in ISO/ASTM Practice cell.
51400, (b) an in-house calibration facility that provides an
10.5.5 Drain the inner compartment and refill it with the
absorbed dose (or an absorbed-dose rate) having measurement
contents of another unirradiated dosimeter.
traceability to nationally or internationally recognized stan-
10.5.6 Connect the digital potentiometer across the cell. If
dards, or (c) a production irradiator under actual production
the electropotential, E, is equal to zero (within 60.2 mV), the
irradiation conditions, together with reference– or transfer-
cell is ready for use. Read at least three unirradiated dosim-
–standard dosimeters that have measurement traceability to
¯
eters, and determine average value E .
o
nationally or internationally recognized standards.
10.5.7 Expel the unirradiated solution from the outer com-
10.3 Measurement Instrument Calibration and Perfor-
partment and draw in the solution from each irradiated dosim-
mance Verification—For the calibration of instruments (spec-
eter (ampoule) in turn, starting with the lowest
...