ISO 15563:1998
(Main)Practice for use of the ethanol-chlorobenzene dosimetry system
Practice for use of the ethanol-chlorobenzene dosimetry system
Pratique de l'utilisation d'un système dosimétrique à l'éthanol chlorobenzène
General Information
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Standards Content (Sample)
INTERNATIONAL ‘IS0
STANDARD 15563
First edition
1998-12-15
Practice for use of the
ethanol-chlorobenzene dosimetry
system
Pratique de l’utilisation d ’un systkme dosimktrique 5 Mhanol
chlorobenz&ne
Reference number
IS0 15563: 1998(E)
---------------------- Page: 1 ----------------------
IS0 15563: 1998(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies
(IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical
committees. Each member body interested in a subject for which a technical committee has been established has
1
the right to be represented on that committee. International organizations, governmental and non-governmental, ir
liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electrotechnica .I
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.
International Standard IS0 15563 was prepared by the American Society for Testing and Materials (ASTM)
Subcommittee E1O.O1 (as E 1538-93) and was adopted, under a special “fast-track procedure ”, by Technical
Committee ISOKC 85, Nuclear energy, in parallel with its approval by the IS0 member bodies.
A new lSO/TC 85 Working Group WG 3, High-level dosimetry for radiation processing, was formed to review the
and to maintain these standards. The USA holds the
voting comments from the IS0 “Fast-track procedure”
convenership of this working group.
International Standard IS0 15563 is one of 20 standards developed and published by ASTM. The 20 fast-tracked
standards and their associated ASTM designations are listed below:
IS0 Designation ASTM Designation Title
Practice for dosimetry in gamma irradiation facilities for food
15554 E 1204-93
processing
15555 E 1205-93 Practice for use of a ceric-cerous sulfate dosimetry system
15556 E 1261-94 Guide for selection and calibration of dosimetry systems for
radiation processing
15557 E 1275-93 Practice for use of a radiochromic film dosimetry system
15558 E 1276-96 Practice for use of a polymethylmethacrylate dosimetry system
15559 E 1310-94 Practice for use of a radiochromic optical waveguide dosimetry
system
E 1400-95a Practice for characterization and performance of a high-dose
15560
radiation dosimetry calibration laboratory
E 1401-96 Practice for use of a dichromate dosimetry system
15561
0 IS0 1998
All rights reserved. Unless otherwise specified, no pa t-t of this publication may be reproduced or utilized in any form or by any means, electronic
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
Of-
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
iso @ isoch
Internet
Printed in Switzerland
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IS0 15563: 1998(E)
as0
E1431-91 Practice for dosimetry in electron and bremsstrahlung irradiation
15562
facilities for food processing
E 1538-93
15563 Practice for use of the ethanol-chlorobenzene dosimetry system
15564 E 1539-93 Guide for use of radiation-sensitive indicators
E 1540-93
15565 Practice for use of a radiochromic liquid dosimetry system
15566 E 1607-94 Practice for use of the alanine-EPR dosimetry system
Practice for dosimetry in an X-ray (bremsstrahlung) facility for
15567 E 1608-94
radiation processing
15568 E1631-96 Practice for use of calorimetric dosimetry systems for electron
beam dose measurements and dosimeter calibrations
15569 E 1649-94 Practice for dosimetry in an electron-beam facility for radiation
processing at energies between 300 ke V and 25 Me V
15570 E 1650-94 Practice for use of cellulose acetate dosimetry system
E 1702-95 Practice for dosimetry in a gamma irradiation facility for radiation
15571
processing
E 1707-95 Guide for estimating uncertainties in dosimetry for radiation
15572
processing
E 1818-96 Practice for dosimetry in an electron-beam facility for radiation
15573
processing at energies between 80 keV and 300 keV
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SO 15563:1998(E)
0 IS0
AMERICAN SOCIETY FOR TE STING AND MATERIALS
Designation: E 1538 - 93
1916 Race St. Philadelphia, Pa 19103
tlslF Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
If not listed in the current combined index, will appear in the next edition.
Standard Practice for
Use of the Ethanol-Chlorobenzene Dosimetry System’
This standard is issued under the fixed designation E 1538; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (0 indicates an editorial change since the last revision or reapproval.
C 9 12 Practice for Designing a Process for Cleaning
1. Scope
Technical Glasses3
1.1 This practice covers the preparation, handling, testing,
D 1193 Specification for Reagent Watefl
and procedure for using the ethanol-chlorobenzene
E 170 Terminology Relating to Radiation Measurements
dosimetry system to measure absorbed dose in materials
and Dosimet$
irradiated by photons and electrons in terms of absorbed
E 275 Practice for Describing and Measuring Performance
dose in water. The system consists of a dosimeter and
of Ultraviolet, Visible, and Near Infrared Spectro-
appropriate analytical instrumentation. For simplicity, the
photometer@
system will be referred to as the ECB system. It is classified as
a reference standard dosimeter (see Guide E I26 1). E 666 Practice for Calculating Absorbed Dose from
1.2 This practice describes the titration analysis as a Gamma or X-Radiation5
standard readout procedure for the ECB dosimeter. Other E 668 Practice for Application of Thermoluminescence
applicable readout methods (spectrophotometric, oscillo- Dosimetry (TLD) Systems for Determining Absorbed
metric) are described in Appendixes Xl and X2. Dose in Radiation-Hardness Testing of Electronic
1.3 This practice applies only to gamma rays, X rays, and
Devices5
high-energy electrons. E 925 Practice for the Periodic Calibration of Narrow
1.4 This practice applies provided the following are satis-
Band-Pass Spectrophotometers7
fied
E 958 Practice for Measuring Practical Spectral Band-
1 .i. 1 The absorbed dose range shall be from 10 Gy to 2
width of Ultraviolet-Visible Spectrophotometers7
MGy (1).2
E 1026 Practice for Using the Fricke Reference Standard
1.4.2 The absorbed dose rate does not exceed lo6 Gy s-l
Dosimetry Systems
(2)
E 1205 Practice for Use of a Ceric-Cerous Sulfate
1.4.3 For radionuclide gamma-ray sources, the initial
Dosimetry Systems
photon energy shall be greater than 0.6 MeV. For
E 126 1 Guide for the Selection and Application of
bremsstrahlung photons, the initial energy of the electrons
Dosimetry Systems for Radiation Processing of Foods
used to produce the bremsstrahlung photons shall be equal to
E 1400 Practice for Characterization and Performance of a
or greater than 2 MeV. For electron beams, the initial
High-Dose Gamma-Radiation Dosimetry Calibration
electron energy shall be greater than 4 MeV (see ICRU
Laboratory5
Reports 34 and 35).
E 1401 Practice for Use of a Dichromate Dosimetry
NOTE I-The lower limits of electromagnetic radiation energy given
Systems
are appropriate for a cylindrical dosimeter ampoule of l&mm diameter.
E 143 1 Practice for Dosimetry in Electron and
Corrections for dose gradients across an ampoule of that diameter or less
Bremsstrahlung Irradiation Facilities for Food Proc-
are not required. The ECB system may be used at energies of incident
essing5
electrons lower than 8 MeV by employing thinner (in the beam
2.2 International Commission on Radiation Units and
direction) dosimeter containers (see ICRU Report 35).
Measurements (ICR U) Reports:
1.4.4 The irradiation temperature of the dosimeter should
ICRU Report 14-Radiation Dosimetry: X-Rays and
be within the range from -40°C to 8O*C.
Gamma Rays with Maximum Photon Energies Between
1.5 This standard does not purport to address all of the
0.6 and 60 MeV7
safity problems, ty any, associated with its use. It is the
ICRU Report 33-Radiation Quantities and Units’
responsibility of the user of this standard to establish appro-
ICRU Report 34-The Dosimetry of Pulsed Radiation’
priate safety and health practices and determine the applica-
ICRU Report 35-Radiation Dosimetry: Electrons with
bility of regulatory limitations prior to use.
Initial Energies Between 1 and 50 MeV7
ICRU Report 37-Stopping Powers for Electrons and
2. Referenced Documents
Positrons7
2.1 ASTM Standards:
3 Annual Book of ASTM Standards, Vol 15.02.
1 This practice is under the jurisdiction of ASTM Committee E-10 on Nuclear 4 Annual Book of ASTM Standards, Vols 02.05, 06.03, 09.0 1, 10.0 1, 10.02,
Technology and Applications and is the direct responsibility of Subcommittee 10.05, 11.01, 11.03, and 15.09.
E 10.0 1 on Dosimetry for Radiation Processing. J Annual Book o/ASTM Standards, Vol 12.02. *
Current edition approved April 15, 1993. Published June 1993. 6 Annual Book o/ASTM Standard, Vol 14.0 1.
2 The boldface numbers in parentheses refer to the list of references at the end 7 Available from the Commission on Radiation Units and Measurements, 79 10
of this practice. Woodmont Ave., Suite 800, Bethesda, MD 208 14.
1
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0 IS0
IS0 15563:1998(E)
value), G(x)-the quotient of the amount n(x), of a sub
3. Terminology
stance, usually a specified molecular species (as a solute in
3.1’ Definitions:
solution), x, produced, destroyed, or changed by radiation,
3.1.1 absorbed dose, D-the quotient of dZ by dm, where
by the mean energy F, imparted to the irradiated matter (see
dZ? is the mean energy imparted by ionizing radiation to the
ICRU Report 33):
matter of mass dm (see ICRU Report 33).
G(x) = n(x)lF
D - & ‘/drn
Unit: mol l J-l
The special unit for absorbed dose is the gray (Gy).
.
DIscussroN-The former special unit was (100 ev)-I. This quantity
1 Gy = 1 &kg-’
is related to the old unit as 1 mole J-l = 9.65 106 mol (100 eV)-l or 1
3.1.2 calibration curve-the graphical or mathematical mol(lO0 eV)-l = 1.036 low7 mol*J-l.
relationship between the net response and the absorbed dose
3.1. I1 reference standard dosimetry system-combina-
for a given dosimetry system. This term is also referred to as
tion of a dosimeter and appropriate analytical instrumenta-
the response function.
tion of high-metrological quality, that is traceable to national
3.1.3 calibration &zcifity-a combination of an ionizing
standards.
radiation source and its associated instrumentation that
3.1.12 traceabilitpthe ability to show that a measure-
provides traceable, uniform, and reproducible absorbed dose
ment is consistent with appropriate national standards
rates at specific locations and in a specific material. It may be
through an unbroken chain of comparisons.
used to calibrate the response of routine or other types of
3.2 For other terms, see Terminology E 170.
dosimeters as a function of absorbed dose.
3.1.4 conductivitpthe conductivity of a solution is usu-
4. Significance and Use
ally defined in terms of specific conductivity (K), which is
given by the conductivity of a solution between electrodes of
4.1 The ECB dosimetry system provides a reliable means
l-cm2 surface area, placed 1 cm from each other.
of measuring absorbed dose in materials. It is based on a
3.1,5 conductometry-analytical method based on the
oric acid (HCl) in
process of radiolytic formation of hydroc
measurement of conductivity of solutions due to the rela-
aqueous ethanolic solutions of chlorobenzene by ionizing
tionship between concentration and conductivity of electro-
radiation (3).
lytes. The conductivity of a solution depends on the concen-
4.2 The dosimeters are partly deoxygenated solutions of
tration of free ions in the solution.
chlorobenzene (CB) in 96 volume % ethanol in an apprs-
3.1.6 dosimetry system-the system used for measuring
priate container, such as a flame-sealed glass ampoule. The
absorbed dose, consisting of dosimeters, measurement in-
solutions indicate absorbed dose by the amount of HCl
strumentation, the calibration curve or specific values of
formed. A number of analytical methods are available for
molar linear absorption coefficient and G-value, reference
measuring the amount of HCl in ethanol (4).
standards, and procedures for the system ’s use.
4.3 The concentration of chlorobenzene in the solution
3.1.7 measurement quality assurance plan-a docu-
can be varied so as to simulate a number of materials in
mented program for the measurement process that quantifies
terms of the photon mass energy-absorption coefficients
the total uncertainty of the measurements (both random and
(cl,&) for X and gamma rays, and electron mass collision
systematic error components). This plan shall demonstrate
stopping powers (l/p) (a/&), over a broad spectral energy
traceability to national standards, and shall show that the
range from 10e2 to 100 MeV (5-7).
total uncertainty meets the requirements of the specific
4.4 The absorbed dose that is measured is the dose
application.
absorbed in the dosimeter. Absorbed dose in other materials
3.1.8 molar linear absorption coeflcient (sometimes called
irradiated under equivalent conditions may be calculated.
molar extinction coefficient), e,-a constant relating the
Procedures for making such calculations are given in Prac-
spectrophotometric absorbance, A,, of an optically absorbing
tices E 666 and E 668 and Guide E 1261.
molecular species, x, at a given wavelength, X, per unit
4.5 There are two factors associated with the use of the
pathlength, d, to the molar concentration, [xl, of that species
ECB system at energies below those specified in 1.4.3:
in its host substance:
4.5.1 The radiation chemical yield may change at low-
photon energies.
4 1
4.5.2 Dose gradients across the dosimeter may require
X-
em = -7 [x]
corrections in dosimeter response at energies below 8 MeV
for electrons.
(unit: L mol-* cmgl or M-l cm-l; SI unit: m2*mol-l)
NOTE 2-For a comprehensive discussion of various dosimetry
where:
methods applicable to.the radiation types and eneIgies discussed in this
A = absorbance at a specified wavelength,
x
practice, see ICRU Reports 14, 17, 34, 35, and 37.
= molar concentration of the species of interest, and
x
1 1
d = optical pathlength within the solution measured by the
5. Interferences
spectrophotometer.
3.1.9 oscillometwan electroanalytical method of con- 5.1 The ECB dosimetric solution response is not particu-
ductivity measurements, when high-frequency (1 to 600
larly sensitive to impurities which occur in commercially
MHz) alternating current is applied to measure or follow available components, chlorobenzene and ethanol of the
analytical reagent (AR) grade purity or equivalent (pro
changes in the composition of chemical systems.
3.1.10 radiation chemical yield (sometimes called Go analysi, p.a., and puriss.). For high-accuracy results, organic
2
2
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@ IS0 IS0 15563:1998(E)
8. Preparation of Dosimeters
materials of technical grade purity (or purum) can be
purified by distillation.
8.1 Dosimeter solutions may contain any concentration
5.2 Care should be exercised in filling ampoules to avoid
of CB. For practical reasons, only several characteristic
depositing solution in the ampoule neck. Subsequent heating
formulations have been thoroughly characterized. Table 1
during sealing of the ampoule may cause an undesirable
lists these typical formulations in terms of CB concentrations
chemical change in the dosimetric solution remaining inside
and radiation chemical yields pertaining to these concentra-
the ampoule ’s neck. Test tubes with ground-glass stoppers
tions.
are therefore preferred to sealed ampoules for measuring
8.2 Prepare 96 volume % aqueous ethanol first by adding
doses below 100 Gy. For the same reason, care should be
absolute ethanol into a volumetric flask containing the
given to avoid heating the body of the ampoule during
appropriate amount of water. Use this aqueous ethanol for
sealing.
making the dosimeter solutions of the desired concentrations
5.3 The dosimetric solution is somewhat sensitive to
by adding it into volumetric flasks containing appropriate
ultraviolet light and should be kept in the dark for long-term
amounts of CB. Store the dosimeter solution in the dark.
storage. No special precautions are required during routine
NOTE 5: Caution-Chlorobenzene is toxic and a skin irritant. Appro-
handling under normal laboratory lighting conditions, but
priate precautions should be exercised in handling it.
strong ultraviolet (UV) sources such as sunlight should be
8.3 Fill the dosimeter ampoules with the dosimeter solu-
avoided (8).
tion. Bubble the solution in the ampoule with nitrogen for
6. Apparatus about 1 min at about 1 bubble per second through a l-mm
capillary. Flame-seal immediately after bubbling. Exercise
6.1 This practice describes mercurimetric titration of
care to avoid depositing solution in the ampoule neck. Store
radiolytically formed Cl- ions as a standard readout proce-
dosimeters in the dark.
dure.
6.2 For the analysis of the dosimetric solution, use a
NOTE 6-Nitrogen may be saturated by passing it through the ECB
solution of the same composition before bubbling the dosimeter
precision burette capable of measuring volumes with O.Ol-
ampoules to avoid changing the composition of dosimeter solution by
mL resolution. If necessary, check the original calibration of
evaporation.
volumetric glassware and, if necessary, recalibrate to attain
0.1 % relative error. Control the temperature of all solutions
9. Calibration of the Mercuric Nitrate Solution
during handling at 20°C.
9.1 The measurement procedure is based on the titration
6.3 Use borosilicate glass or equivalent chemically resis-
of chloride ions formed by irradiation. Free chloride is
tant glass to store the reagents, the prepared dosimeter
solution, and to perform the titration. Clean all apparatus precipitated with mercuric ions as insoluble HgC12, where-
thoroughly before use (see Practice C 9 12). upon the excess of Hg2+ ions gives a violet-red coloration
6.4 Use a sealed glass ampoule or other appropriate glass with the indicator diphenylcarbazone in acid medium (11).
9.2 Prepare approximately 5 x 1 Om4 mol l drnB3 Hg(N03)2
container to hold the dosimetric solution during irradiation.
in acidic aqueous ethanol. First dissolve an appropriate
For photons, surround the container with material of thick-
amount of Hg(N03)2 in water acidified with sufficient HN03
ness sufficient to produce approximate electron equilibrium
conditions during calibration irradiations. For measurement to attain the concentration of the acid in the final solution,
of absorbed dose in water, use materials that have radiation- 0.05 mol l dmW3.
absorption properties essentially equivalent to water, for
NOTE 7: Caution-Mercuric (II) nitrate is highly toxic. Acute expo-
example, polystyrene and polyethylene. The appropriate
sure of skin and mucous membranes produces violent corrosive effects.
thickness of such material depends on the energy of the
Chronic exposure causes many pathological changes. Appropriate pre-
photon radiation (see Practices E 666 and E 668). cautions should be exercised in handling it. Hazards of mercury
poisoning can be avoided by using some of the alternative readout
NOTE 3-The dosimetric ampoule commonly used has a capacity of
methods described in Appendixes Xl and X2.
about 5 mL.
TABLE 1 Typical ECB Solution Formulations
7. Reagents
Radiation Chemical YiekW
7.1 Analytical reagent grade chemicals shall be used in
@T&J- ‘)
Concentration Density at Ratio of
this practice for preparing all solutions.8
of CB, vd % 20°C kg*m-3 coefficients fA
%ogamma 4toloMeV
7.2 Use of triply distilled water from coupled all-glass stills
rays (9) electrons (10)
is recommended. Type II reagent water as specified in
0.989 0.42c
4 819
Specification D 1193 is also considered to be of sufficient
839 0.995 0.52
10
0.59
20 869 1.006
quality for use in preparing solutions and 96 volume %
1.011 0.60 0.570
24 880
ethanol.
925 1.027 0.63
40
NOTE 4-High-purity water is commercially available from some
AThe ratio of the mass energy-absorption coefficients for water and the
suppliers. Such water, labelled HPLC (high-pressure liquid chromatog- dosimeter solution
at Wo gamma ray energy:
raphy) grade, is usually sufficiently free of impurities to be used in this
practice.
e$?
!I D
* Radiation chemical yields of HCI in the dose range from 100 Gy to 100 kGy.
c Upper dose range 20 kGy.
* Reagent specifications are available from the American Chemical Society, D Lower dose range 1 kGy. This formulation also contained 0.04 volume %
1115 16th Street, NW, Washington, DC 20036. acetone and 0.04 vdume % benzene.
3
3
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IS0 15563:1998(E) 0 IS0
eters during irradiation. Take into account any temperature
9.2.1 Prepare standard solutions of NaCl in water. Make
variations beyond the 18 to 30°C range that Sect dosimeter
several concentrations to enable cross-checking. Suitable
response. The temperature dependence of dosimeter re-
concentrations are 5 x 10e3, 1 .O x 10w2, 1.5 X 10w2, and 2.0
sponse during irradiation between 20 and 8Q ”C is found in
x 10e2 mol*dm- 3. If kept properly in ground-glass stoppered
4)9 and between -40 and 20°C i
bottles, these solutions are stable for years Avoid contami-
set of at least three
nation of the standard solutions by using for d
small portions of these solutions kept in small gr
stoppered flasks. Replenish standard solutions in the small
known dose values coverin
flasks as necessary.
to
9.2.2 Prepare 0.2 mol edrnw3 HN03 in ethanol an
ethanolic solution of diphenylcarbazone (DPC).
SYS
9.3 Distribute technical grade ethanol to beakers for
NOTE l&-The observed dose can in principle determined with
titration, 10 mL into each, Pipet standard NaCl solution the ethansl-chlorobenzene dosimeter without the necessity for calibra-
tion of the dosimeter response, if procedures outlinti in Sections 5,4,7,
uantitatively to beakers with ethanol. Add 1 mL of 0.2 M
8, 9, and 10 are adhered to. However, it is prudent to assure that the
HN03 and 7 drops of 1 % DPC and shake. Titrate with
dosimeter is behaving as expected. Calibration would also be 1pecezzu-y if
Hg(N03)* solution from the burette. The solution in the
a formulation of the ent from any one listed in
beaker which is initially yeilow-orange turns to reddish-violet
rs in a known
Table 1 is used. Thi
at the end point.
radiation field of a res sf 10.8 to
9.4 Construct or calculate the best straight line through
perf~rrn the irradiations. Only a few dose levels are needed to check both
the points: (consumption of Hg(N03)2) versus (milliequi- the absolute response and the linearity of the dssimeter. Analye the
dosimeters and calculate the doses using the procedures of 10.2 and
valents of NaCl). The small positive intercept represents the
10.3. Compare the resuhs with the calibration doses. The results from
blank; inverse slope gives concentration of Hg(NO,), solu-
the two methods should not difI ’er by more than the overall uncertainty
tion.
of the dosimeter response. If the difference is greater, there is an
NATE 8-Volumes of the standard NaCll solutions should be such
indication of possible contaminatiom of the solution, or some other
that the consumption of the titrant solution on calibration are similar to problem must t resolved.
the consumptions when analyzing irradiated dosimetric solutions. Take
10.2 Measurement-Transfer the irradiated dosimeter so-
two different volumes of each standard solution to enable cross-
lution quantitatively into a beaker for titration. Rinse the
checking. The concentration of mercuric nitrate solution should be
dosimeter ampoule several times with 5 mL of technical
calibrated daily.
grade ethanol, so that the final volume in the beaker is 10
1.0. Irradiation and Measurement Procedures
mL. Add 1 mL of 0.2 M HN03 and 7 drops of DPC and
10.1 Calibration of the Dosimeter Response: titrate to the same ‘color change as that observed during
calibration of the mercuric nitrate solution.
10.1.1 Calibrate the dosimeters using an irradiation fa-
cility that has a dose rate traceable to national standards and
NOTE 1 l-If high doses are to be measured, use appropriate portions
that meets the requirements specified in Practices E 1400
of irradiated dosimeter solution, taking care that total volume in the
beaker is 10 mL.
and E 143 1. Use a reference or transfer dosimetry system to
establish this traceability (see Guide E 126 1 and Practices
10.3 Analysis:
E 1026, E 1205, and E 1401).
10.3.1 Subtract the blank from the amounts of Hg(N03)2
10.1.2 Specify the dose in terms of absorbed dose in water
of
solution consumed and calculate the concentration
(for example, see Practices E 1026, E 1205, and E 140 1).
radiolytically formed Cl- ions in each dosimeter:
10.1.3 Position the dosimeters in the radiation field in a
(mL of titrant) - (blank)
equivalents
defined, reproducible location (12). b
of a- ’ mL of dosimetric solution
10.1.4 When using a gamma-ray source for irradiation of
very thin dosimeters (for example, in capillaries), sumound Calculate the absorbed dose in the dosimeter as follows:
the dosimeters with a sufficient amount of water-equivalent
IF%
material to achieve approximate electron equilibrium condi-
=-
D
(2)
tions.
aCuJ
NOTE g--The appropriate thickness of such material. depends on the The values of G(HC1) and p are found in Table 1 or in the
energy of the radiation (see Practices E 666 and E 668). For measure-
literature (1, 5). Other values can be derived in accordance
ment of absorbed dose in water use materials that have radiation-
with 10.1,
absorption properties essentially equivalent to those of water. For
10.3.2 To calculate the absorbed dose in water (ICRU
example, for a To source, 3 to 5 mm of polystyrene (or equivalent
Report 14) use the following:
polymeric material) should surround the dosimeter in all directions.
D, =j-a
(3
10.1.5 When using an electron beam for irradiation,
where $ is the ratio of photon mass energy-absorption
locate the dosimeters in a well-characterized position within
coefficients for water and that for the dosimeter. The values
the radiation field (13). In addition, it may be necessary to
surround the dosimeter(s) with water-equivalent material. of factor Iat the reference energy, 1.25 MeV, are found in
10.1.6 Make the irradiation field within the volume Table 1 0
occupied by the dosimeter(s) as uniform as possible, The
. Minimum Documentation Require
variation in dose rate within this volume should be within
-el %. B 1 e 1 Calibration of the Dosimeter Response (f Per-
10.1.7 Control (or monitor) the temperature of the dosim- formed):
4
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IS0 15563: 1998(E)
0 IS0
11.1.1 Record the dosimeter type and batch number shall be accompanied by an estimate of the uncertainty in
the measured value. Factors contributing to the total uncer-
(code).
s, precision (random)
11.1.2 Record or reference the date, irradiation tempera- tainty may be separated into two
dixusses sources of
ture, temperature variation (if any), dose range, radiation and bias (systematic). Guide E 1
uncertainty and lists some of the possible factors that ;affect
source (inciudin dose rate and energy), and associated
dditional information is given in
instrumen+tation used to calibrate and analyze the dosime- precision and bias.
ters. Practice E 668 and Refs (16) and
12-2 The random and systematic uncertainties involved
11.2 Application:
in mea+.ing absorbed dose using this dosimetry system
11.2,l Record the date and temperature of irradiation,
should be estimated or determined. The overall uncertainty
temperature variation (if any), and the date and temperature
in absorbed dose should be estimated from a combination of
of absorbance measurement, for each dosimeter.
and these uncertainties, and the procedure for combining these
ecord or reference the ra
uncertainties should be specifically stated or referenced for
its.
all results.
ecord the consumption of the titrant, net con-
12.3 If care is taken in carrying out this practice, the
sumption value, temperature cone&ion (if applicable), and
combined uncertainty of an absorbed dose evaluated by the
resulting absorbed dose for each dosimeter. Reference the
calibration curve (if appropriate) or the calculations used to dosimetry system should be within zt3 % at a 95 % confi-
obtain the absorbed-dose values. dence level. This combined un?etinty is based on an
11.2.4 Record or reference the precision and bias in the uncertainty of k2 % at a 95 % confidence level for the dose
value of the absorbed dose. rate of the calibration source.
11.2.5 Record or reference the measurement quality as-
13. Keywords
surance plan used for the dosimetry system application.
13.1 absorbed dose; dose; dose measurement; dosimeter;
dosimetry system; ECB; electron beam; ethanol-chloro-
benze
...
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