1、ISO/ASTM 51540:2004 (Reapproved 2012)(E)Standard Practice forUse of a Radiochromic Liquid Dosimetry System1This standard is issued under the fixed designation ISO/ASTM 51540; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year
2、 of last revision.1. Scope1.1 This practice covers the procedures for preparation,handling, testing, and using radiochromic liquid dosimetrysystems of radiochromic dye solutions held in sealed or cappedcontainers (for example, ampoules, vials). It also covers the useof spectrophotometric or photomet
3、ric readout equipment formeasuring absorbed dose in materials irradiated by photonsand electrons.1.2 This practice applies to radiochromic liquid dosimetersolutions that can be used within part or all of the specifiedranges as follows:1.2.1 The absorbed dose range is from 0.5 to 40 000 Gy forphotons
4、 and electrons.1.2.2 The absorbed dose rate is from 103to 1011Gy/s.1.2.3 The radiation energy range for photons is from 0.01 to20 MeV.1.2.4 The radiation energy range for electrons is from 0.01to 20 MeV.NOTE 1Since electrons with energies less than 0.01 MeV may notpenetrate the container of the solu
5、tion, the solutions may be stirred in anopen beaker with the electrons entering the solutions directly (1).21.2.5 The irradiation temperature range is from 40 to+60C.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of t
6、he user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced documents2.1 ASTM Standards:3C912 Practice for Designing a Process for Cleaning Techni-cal GlassesE170 Terminology Relating to Radiatio
7、n Measurements andDosimetryE275 Practice for Describing and Measuring Performance ofUltraviolet and Visible SpectrophotometersE666 Practice for Calculating Absorbed Dose From Gammaor X RadiationE668 Practice for Application of Thermoluminescence-Dosimetry (TLD) Systems for Determining AbsorbedDose i
8、n Radiation-Hardness Testing of Electronic DevicesE925 Practice for Monitoring the Calibration of Ultraviolet-Visible Spectrophotometers whose Spectral Bandwidthdoes not Exceed 2 nmE958 Practice for Estimation of the Spectral Bandwidth ofUltraviolet-Visible SpectrophotometersE1026 Practice for Using
9、 the Fricke Dosimetry System2.2 ISO/ASTM Standards:351261 Guide for Selection and Calibration of DosimetrySystems for Radiation Processing51400 Practice for Characterization and Performance of aHigh-Dose Gamma Radiation Dosimetry CalibrationLaboratory51707 Guide for Estimating Uncertainties in Dosim
10、etry forRadiation Processing2.3 International Commission on Radiation Units and Mea-surements (ICRU) Reports:4ICRU Report 14 Radiation Dosimetry: X-Rays and GammaRays with Maximum Photon Energies Between 0.6 and 50MeVICRU Report 17 Radiation Dosimetry: X-Rays Generated atPotentials of 5 to 150 kV1Th
11、is practice is under the jurisdiction of ASTM Committee E61 on RadiationProcessing and is the direct responsibility of Subcommittee E61.02. on , and is alsounder the jurisdiction of ISO/TC 85/WG 3.Current edition approved March 21, 2012. Published November 2012. Originallypublished as E 1540 93. Las
12、t previous ASTM edition E 1540981. ASTME 154093 was adopted by ISO in 1998 with the intermediate designation ISO15565:1998(E). The present International Standard ISO/ASTM51540:2004(2012)(E) replaces ISO 15565 and is a reapproval of the last previousedition ISO/ASTM 51540:2004(E).2The boldface number
13、s in parentheses refer to the bibliography at the end of thispractice.3For referenced ASTM and ISO/ASTM standards, visit the ASTM website,www.astm.org, or contact ASTM Customer Service at serviceastm.org. ForAnnual Book of ASTM Standards volume information, refer to the standardsDocument Summary pag
14、e on the ASTM website.4Available from the International Commission on Radiation Units andMeasurements, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814, U.S.A. ISO/ASTM International 2017 All rights reservedThis international standard was developed in accordance with internationally recognized prin
15、ciples on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1ICRU Report 34 The Dosimetry of Pulsed RadiationICRU Report 35 Radiation D
16、osimetry: Electron Beams withEnergies between 1 and 50 MeVICRU Report 37 Stopping Powers for Electrons and PhotonsICRU Report 44 Tissue Substitutes in Radiation Dosimetryand MeasurementICRU Report 60 Fundamental Quantities and Units forIonizing Radiation3. Terminology3.1 Definitions:3.1.1 calibratio
17、n curvegraphical representation of the do-simetry systems response function.3.1.2 dosimeter batchquantity of dosimeters made from aspecific mass of material with uniform composition, fabricatedin a single production run under controlled, consistent condi-tions and having a unique identification code
18、.3.1.3 dosimetry systemsystem used for determining ab-sorbed dose, consisting of dosimeters, measurement instru-ments and their associated reference standards, and proceduresfor the systems use.3.1.4 measurement quality assurance plandocumentedprogram for the measurement process that ensures on acon
19、tinuing basis that the overall uncertainty meets the require-ments of the specific application. This plan requires traceabilityto, and consistency with, nationally or internationally recog-nized standards.3.1.5 molar linear absorption coeffcient (m)constant re-lating the spectrophotometric absorbanc
20、e, A, of an opticallyabsorbing molecular species at a given wavelength () per unitpathlength (d) to the molar concentration, c, of that species insolution (2-4): m=A/(dc). SI Unit: m2mol1.3.1.6 net absorbance, Achange in measured optical ab-sorbance at a selected wavelength determined as the absolut
21、edifference between the pre-irradiation absorbance, A0, and thepost-irradiation absorbance, A, as follows (2, 3): A=|AA0|.3.1.7 radiochromic liquid dosimeterspecially prepared so-lution containing ingredients that undergo change in opticalabsorbance under ionizing radiation. This change in opticalab
22、sorbance can be related to absorbed dose in water.3.1.8 response functionmathematical representation of therelationship between dosimeter response and absorbed dose fora given dosimetry system.3.1.9 specific net absorbance (k)Net absorbance, A,ata selected wavelength divided by the optical pathlengt
23、h, d,through the dosimeter material as follows: k=A/d.3.2 Definitions of other terms used in this standard thatpertain to radiation measurement and dosimetry may be foundin ASTM Terminology E170. Definitions in E170 are compat-ible with ICRU 60; that document, therefore, may be used as analternative
24、 reference.4. Significance and use4.1 The radiochromic liquid dosimetry system provides ameans of measuring absorbed dose in materials (5-7). Underthe influence of ionizing radiation, chemical reactions takeplace in the radiochromic solution modifying the amplitudes ofoptical absorption bands (8-10)
25、. Absorbance values are mea-sured at the selected wavelength(s) within these affectedabsorption bands (see also ISO/ASTM Guide 51261).4.2 In the use of a specific dosimetry system, a calibrationcurve or response function relates the dosimeters response toan absorbed dose traceable to a nationally or
26、 internationallyrecognized standard (11, 12).4.3 The absorbed dose that is measured is usually specifiedin water.Absorbed dose in other materials may be evaluated byapplying the conversion factors discussed in ISO/ASTM Guide51261.NOTE 2For a comprehensive discussion of various dosimetry methodsappli
27、cable to the radiation types and energies discussed in this practice,see ICRU Reports 14, 17, 34, 35, and 37.4.4 These dosimetry systems may be used in the industrialradiation processing of a variety of products, for example thesterilization of medical devices and radiation processing offoods (5, 7,
28、 13).4.5 The available dynamic range indicated in 1.2.1 isachieved by using a variety of radiochromic leuco dyes (Table1) in a variety of solutions (Table 2).4.6 The ingredients of the solutions, in particular thesolvents, can be varied so as to simulate a number of materialsin terms of the photon m
29、ass energy-absorption coefficients,(en/), for X-rays and gamma-rays and electron mass collisionstopping powers, (1/) dE/dx, over a broad spectral energyrange from 0.01 to 100 MeV (18). For special applicationscertain tissue-equivalent radiochromic solutions have beendesigned to simulate various mate
30、rials and anatomical tissues,in terms of values of (en/) for photons and (1/) dE/dx forelectrons (18) (see also ICRU Report 44). Tabulations of thevalues of (en/) for water (19), the anatomical tissues (17, 19),and three specially designed radiochromic solutions, for pho-tons over the energy range f
31、rom 0.01 to 20 MeV, andtabulations of the values of (1/) dE/dx (17) for water, thetissues and the radiochromic solutions for electrons over theenergy range from 0.01 to 20 MeV are given in Refs (12, 13,18). For additional information see ISO/ASTM Guide 51261,ASTM Practice E666, and ICRU Reports 14,
32、17, 35, 37, and44.5. Apparatus5.1 The following shall be used to determine absorbed dosewith radiochromic liquid dosimetry systems:5.1.1 Batch or Portion of a Batch of Radiochromic Liquid.5.1.2 Spectrophotometer or Photometer, having documenta-tion covering analysis wavelengths, accuracy of waveleng
33、thselection, absorbance determination, analysis bandwidth, andstray light rejection. The spectrophotometer should be able toread visible spectrum absorbance values of up to 2 with anuncertainty of no more than 61%.5.1.3 Glass Cuvettes, having optical windows and pathlengths of 5 to 100 mm, depending
34、 on the dose range of interestand on the size of the dosimeter ampoule used for irradiation.ISO/ASTM 51540:2004 (2012)(E)2 ISO/ASTM International 2017 All rights reserved Glass flow cells with parallel optical windows may be analternative means of holding the solutions for spectrophotom-etry.5.1.4 C
35、lean glass containers may be used for storage orirradiation of the solutions.5.1.4.1 Containers for storing the solutions should haveglass, aluminum, or polyethylene liners for the lids. The lidsshould be compatible with the unirradiated and irradiatedsolution.5.1.4.2 Use glass ampoules which are fl
36、ame sealed forcontaining the solution during irradiation, or alternatively,glass vials with lids having aluminum or polyethylene liners, ordisposable plastic vials, using only polymeric materials knownto be resistant to any chemical effects by the solvents that areused.Another type of container for
37、irradiation may be a cuvetteequipped with a tightly closed cap. The solution should bestored at 300C) and cooled toambient laboratory temperature before being used to hold the dosimetricsolution. For more detail on cleaning glassware, seeASTM Practice C912.NOTE 4The glass ampoules or vials for irrad
38、iation commonly havecapacities of 2 to 5 mL. The glass is commonly amber to protect thesolution from stray ultraviolet light.TABLE 1 Three Available Radiochromic Leuco Dyes, Their Molecular Structures, Molecular Weights, and Values of mand Color IndexNumbers of the Parent Dyes (14, 15)Radiochromic L
39、euco Dye (code) Molecular Structure Molecular WeightMolar Linear AbsorptionCoefficientA(L mol1cm1)Color Index No.Pararosaniline cyanide (PRC) (See diagram below left) 314.376 140 000 ( = 550 nm) 42 500Hexa(hydroxyethyl)pararosanilinecyanide (HHEVC)(See diagram below center) 578.715 100 000 ( = 600 n
40、m) (none given)New fuchsin cyanide (NFC) (See diagram below right) 356.455 130 000 ( = 560 nm) 42 500AThese values of molar linear absorption coefficients are given in Ref (14, 16) for 2-methoxyethanol solutions containing 17 mM acetic acid. The values may vary somewhatin other solvents and with oth
41、er additives.TABLE 2 Selected Radiochromic Solution Formulations and the Radiation Chemical Yields of Dye Cations in SolutionRadiochromicLeuco Dye(See Table 1)Solution FormulationRadiochromic LeucoDye Concentration(mmol L1)Wavelength forSpectrophotometer,nmRadiation ChemicalYield, mol J1Nominal Dose
42、Range, GyReferencesHHEVC Dissolve in 2-methoxy ethanol containing 17 mmolL1acetic acid5 599 0.025 101000 (5)PRC Dissolve in 2-methoxy ethanol containing 51 mmolL1acetic acid5 549 0.033 103000 (1)NFC Dissolve in dimethyl sulfoxide containing 17 mmolL1acetic acid0.1 554 0.0031 10030 000 (14)PRC Dissol
43、ve in dimethyl sulfoxide containing 17 mmolL1acetic acid and 30 mmol L1nitrobenzene5 554 0.0040 340 000 (11)HHEVC Dissolve in mixture of 85 % n-propanol and 15 %triethylphosphate (by volume), containing 34mmol L1acetic acid, 500 parts-per-millionnitrobenzoic acid and 10 % polyvinyl butyral (byweight
44、)2 605 0.0051 505000 (15)NFC Dissolve in mixture of 85 % triethylphosphate and15 % dimethyl sulfoxide (by volume), containing68 mM acetic acid, 500 parts-per-millionnitrobenzoic acid and 10 % polyvinyl butyral (byweight)2 557 0.0055 10010 000 (12)HHEVC Dissolve in mixture of 85 % triethylphosphate a
45、nd15 % dimethyl sulfoxide (by volume), containing68 mM acetic acid, 500 parts-per-millionnitrobenzoic acid and 10 % polyvinyl butyral (byweight)100 608 0.28 0.510 (17)ISO/ASTM 51540:2004 (2012)(E)3 ISO/ASTM International 2017 All rights reserved 6. Performance check of instrumentation6.1 Check and d
46、ocument the performance of the photometeror spectrophotometer. (For detailed information on these per-formance checks, seeASTM Practices E275, E925, and E958.)Use reference standards traceable to national or internationalstandards.6.1.1 When using a photometer, estimate and document theaccuracy of t
47、he absorbance at time intervals not to exceed onemonth during periods of use, or whenever there are indicationsof poor performance.6.1.2 When using a spectrophotometer, estimate and docu-ment the accuracy of the wavelength and absorbance at or nearthe selected analysis wavelength(s) at time interval
48、s not toexceed one month during periods of use, or whenever there areindications of poor performance.6.1.3 Document the comparison of information obtained in6.1.1 or 6.1.2 with the original instrument specification toverify adequate performance and take appropriate correctiveaction if required.7. Pr
49、eparation of dosimeters7.1 SolventsThe solvents for dissolving radiochromic dyeprecursors include a number of liquid polar organic solvents,reagent grade or better. Examples include: ethanol,isopropanol, n-propanol, 2-methoxyethanol, 2-ethoxy-ethanol,N,N-dimethylformamide, dimethylsulfoxide, triethylphosphate(1, 9-11, 14-16, 18). The choice of the so
