ANSI ISO ASTM 51310-2004 Standard Practice for Use of a Radiochromic Optical Waveguide Dosimetry System.pdf

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1、ISO/ASTM 51310:2004 (Reapproved 2012)(E)Standard Practice forUse of a Radiochromic Optical Waveguide DosimetrySystem1This standard is issued under the fixed designation ISO/ASTM 51310; the number immediately following the designation indicates theyear of original adoption or, in the case of revision

2、, the year of last revision.1. Scope1.1 This practice covers the procedures for handling,testing, and using a radiochromic optical waveguide dosimetrysystem to measure absorbed dose in materials irradiated byphotons in terms of absorbed dose in water.1.2 This practice applies to radiochromic optical

3、 waveguidedosimeters that can be used within part or all of the specifiedranges as follows:1.2.1 The absorbed dose range is from 1 to 10 000 Gy forphotons.1.2.2 The absorbed dose rate is from 0.001 to 1000 Gy/s.1.2.3 The radiation energy range for photons is from 0.1 to10 MeV.1.2.4 The irradiation t

4、emperature range is from 78 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 the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limit

5、ations prior to use.2. Referenced documents2.1 ASTM Standards:2E170 Terminology Relating to Radiation Measurements andDosimetryE275 Practice for Describing and Measuring Performance ofUltraviolet and Visible SpectrophotometersE668 Practice for Application of Thermoluminescence-Dosimetry (TLD) System

6、s for Determining AbsorbedDose in 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 Spectropho

7、tometersE1026 Practice for Using the Fricke Dosimetry System2.2 ISO/ASTM Standards:251261 Guide for Selection and Calibration of DosimetrySystems for Radiation Processing51400 Practice for Characterization and Performance of aHigh-Dose Radiation Dosimetry Calibration Laboratory51707 Guide for Estima

8、ting Uncertainties in Dosimetry forRadiation Processing2.3 International Commission on Radiation Units and Mea-surements (ICRU) Reports:3ICRU Report 14 Radiation Dosimetry: X-Rays and GammaRays with Maximum Photon Energies Between 0.6 and 50MeVICRU Report 17 Radiation Dosimetry: XRays Generated atPo

9、tentials of 5 to 150 kVICRU Report 34 The Dosimetry of Pulsed RadiationICRU Report 60 Fundamental Quantities and Units forIonizing Radiation3. Terminology3.1 Definitions:3.1.1 analysis wavelengthwavelength used in a spectro-photometric instrument for the measurement of optical absor-bance or reflect

10、ance.3.1.2 calibration curvegraphical representation of the do-simetry systems response function.3.1.3 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 uniqu

11、e identification code.3.1.4 dosimetry systemsystem used for determining ab-sorbed dose, consisting of dosimeters, measurement instru-ments and their associated reference standards, and proceduresfor the systems use.1This guide is under the jurisdiction of ASTM Committee E61 on RadiationProcessing an

12、d is the direct responsibility of Subcommittee E61.02 on DosimetrySystems, and is also under the jurisdiction of ISO/TC 85/WG 3.Current edition approved March 21, 2012. Published November 2012. Originallypublished as ASTM E 131089. Last previous ASTM edition E 1310981. ASTME 131094 was adopted by IS

13、O in 1998 with the intermediate designation ISO15559:1998(E). The present International Standard ISO/ASTM51310:2004(2012)(E) replaces ISO 15559 and is a reapproval of the last previousedition ISO/ASTM 51310:2004(E).2For referenced ASTM and ISO/ASTM standards, visit the ASTM website,www.astm.org, or

14、contact ASTM Customer Service at serviceastm.org. ForAnnual Book of ASTM Standards volume information, refer to the standardsDocument Summary page on the ASTM website.3Available from the International Commission on Radiation Units andMeasurements, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814, U

15、.S.A. ISO/ASTM International 2017 All rights reservedThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the

16、 World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.5 measurement quality assurance plandocumentedprogram for the measurement process that ensures on acontinuing basis that the overall uncertainty meets the require-ments of the specific application. This plan requires traceabi

17、lityto, and consistency with, nationally or internationally recog-nized standards.3.1.6 net response, R radiationinduced change in therelationship of measured absorbance at a specific wavelengthdetermined by subtracting the preirradiation response, R0,from the postirradiation response, R:R 5 R 2 R0(

18、1)with:R 5AArefR0 5FAArefG0(2)and where:A= optical absorbance at the analysis wavelength, , andAref= optical absorbance at a reference wavelength, ref.3.1.7 optical waveguidedevice that contains an opticalpath at a high index of refraction relative to the materialenclosing the optical path.3.1.8 rad

19、iochromic optical waveguidespecially preparedoptical waveguide containing ingredients that undergo anionizing radiationinduced change in photometric absorbance.This change in absorbance can be related to absorbed dose inwater (1, 2).43.1.9 reference wavelength, refwavelength selected forcomparison w

20、ith the analysis wavelength. This wavelength ischosen to minimize effects associated with optical couplingand other geometric variations in the dosimeter.3.1.10 response functionmathematical representation ofthe relationship between dosimeter response and absorbed dosefor a given dosimetry system.3.

21、2 Definitions or 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 reference.4. Significance and use4.1 The radiochromic o

22、ptical waveguide dosimetry systemprovides a means of measuring absorbed dose in materials.Under the influence of ionizing radiation such as photons,chemical reactions take place in the radiochromic opticalwaveguide creating and/or modifying optical absorbance bandsin the visible region of the spectr

23、um. Optical response isdetermined at selected wavelengths using the equations in3.1.6. Examples of appropriate wavelengths for the analysis forspecific dosimetry systems are provided by their manufacturersand in Refs (1-5).4.2 In the application of a specific dosimetry system,absorbed dose is determ

24、ined by use of a calibration curvetraceable to national or international standards.4.3 The absorbed dose determined is usually specified inwater. Absorbed dose in other materials may be determined byapplying the conversion factors discussed in ISO/ASTM Guide51261.NOTE 1For a comprehensive discussion

25、 of various dosimetry methodsapplicable to the radiation types and energies discussed in this practice,see ICRU Reports 14, 17, and 34.4.4 These dosimetry systems commonly are applied in theindustrial radiation processing of a variety of products, forexample, the sterilization of medical devices and

26、 radiationprocessing of foods (4-6).5. Apparatus5.1 The following shall be used to determine absorbed dosewith radiochromic optical waveguide dosimetry systems:5.1.1 DosimetersA batch or portion of a batch of ra-diochromic optical waveguide dosimeters.5.1.2 Spectrophotometer or PhotometerAn instrume

27、nt,either a spectrophotometer equipped with a special dosimeterholder and associated coupling optics (see Ref 7 for anexample), or a modified photometer (see Fig. 1 for a blockdiagram of an instrument that uses a reference wavelength),having documentation covering analysis wavelengths, accu-racy of

28、wavelength selection, absorbance determination, spec-tral bandwidth, and stray light rejection.5.1.3 Holder, to position the dosimeter reproducibly in themeasuring light beam.6. Performance check of instrumentation6.1 Check and document the performance of the photometeror spectrophotometer (see ASTM

29、 Practices E275, E925, E958,and E1026). Use reference standards traceable to national orinternational standards, unless the photometers or spectropho-tometers design precludes such use.6.1.1 When using a photometer, check and document theaccuracy of the absorbance scale at intervals not to exceed on

30、emonth during periods of use, or whenever there are indicationsof poor performance.4The boldface numbers in parentheses refer to the bibliography at the end of thispractice. FIG. 1 Block Diagram of the Instrument Described in Section 5ISO/ASTM 51310:2004 (2012)(E)2 ISO/ASTM International 2017 All ri

31、ghts reserved 6.1.2 When using a spectrophotometer, check and documentthe precision and bias of the wavelength scale and absorbancescale at or near the selected analysis wavelength(s) at intervalsnot to exceed one month during periods of use, or wheneverthere are indications of poor performance.6.1.

32、3 Document the comparison of information obtained in6.1.1 or 6.1.2 with the original instrument specification toverify adequate performance.7. Calibration of the dosimetry system7.1 Prior to use, the dosimetry system (consisting of aspecific batch of dosimeters and specific measurement instru-ments)

33、 shall be calibrated in accordance with the usersdocumented procedure that specifies details of the calibrationprocess and quality assurance requirements. This calibrationprocess shall be repeated at regular intervals to ensure that theaccuracy of the absorbed dose measurement is maintainedwithin re

34、quired limits. Calibration methods are described inISO/ASTM Guide 51261.7.2 Calibration of DosimetersIrradiation is a critical com-ponent of the calibration of the dosimetry system. Calibrationshall be performed in one of three ways by irradiating thedosimeters at:7.2.1 an accredited calibration lab

35、oratory that provides anabsorbed dose (or an absorbed-dose rate) having measurementtraceability to nationally or internationally recognizedstandards, or7.2.2 an in-house calibration facility that provides an ab-sorbed dose (or an absorbed-dose rate) having measurementtraceability to nationally or in

36、ternationally recognizedstandards, or7.2.3 a production or research irradiation facility togetherwith reference or transfer standard dosimeters that have mea-surement traceability to nationally or internationally recog-nized standards.7.3 When the optical waveguide dosimeter is used as atransfer sta

37、ndard dosimeter, the calibration irradiation may beperformed only as stated in 7.2.1,orin7.2.2 at a facility thatmeets the requirements in ISO/ASTM Practice 51400.7.4 Measurement Instrument Calibration and PerformanceVerificationFor the calibration of the instruments, and for theverification of inst

38、rument performance between calibrations,see ISO/ASTM Guide 51261 and/or instrument-specific oper-ating manuals.8. Procedure8.1 Examination and Storage Procedure:8.1.1 Exposure to ultraviolet (UV) radiation may cause thedosimeter to change color. Perform tests to ensure that thehandling and reading e

39、nvironment does not cause measurablecolor development. If needed, place UV filters over fluorescentlights or windows to reduce color development.NOTE 2Dosimeters may be stored in UVopaque material to furtheravoid the effects noted in 8.1.1.8.1.2 Handle the dosimeter along the sides, never at theends

40、. Handling should be kept to a minimum.8.1.3 Visually inspect the dosimeters for imperfections (forexample, loss of end fittings). Discard any dosimeters thatshow imperfections.8.1.4 Identify the dosimeters with an appropriate code thatcan be related to the manufacturer, type, and batch.8.1.5 Store

41、the dosimeters in accordance with the manufac-turers written recommendations.8.2 Irradiation Procedure:8.2.1 Determine the pre-irradiation response, R0, for eachdosimeter at the selected analysis wavelength(s). This may bedone for each dosimeter or by use of an average R0determinedby reading several

42、 dosimeters and documenting theuncertainty, provided this practice meets the precision require-ments for the application.8.2.2 Where necessary, package the dosimeters in a UV-opaque material.8.2.3 Mark the packaged dosimeters appropriately for iden-tification.8.2.4 Irradiate the dosimeters.NOTE 3The

43、 dosimeters may be irradiated in the product undergoingprocessing or in a medium of similar composition, or water, of appropriatedimensions so as to approximate electron equilibrium conditions. Suchequilibrium conditions may not exist within dosimeters placed throughoutthe product under actual proce

44、ssing conditions. This particularly is thecase near interfaces of different materials. Irradiation under nonequilib-rium conditions, such as on the surface of a product package, is often usedto monitor the absorbed dose delivered to the product and may be relatedto the absorbed dose within the produ

45、ct by correction factors under certainconditions.8.3 Analysis Procedure:8.3.1 Avoid any exposure to stray ultraviolet radiation thatmay induce coloration of the dosimeter (see 8.1.1).8.3.2 Determine the post-irradiation response, R,attheselected analysis wavelength(s) used for calibration of thedosi

46、metry system.8.3.3 Calculate the net response, R, as follows:R 5 R 2 R0(3)8.3.4 Determine the absorbed dose from the calibrationcurve or response function.9. Characterization of each batch of dosimeters9.1 Reproducibility of Net Response:9.1.1 Determine the reproducibility of net response for eachba

47、tch of dosimeters by analyzing the data from the sets ofdosimeters irradiated during the calibration process at eachdose value.9.1.2 Use the sample standard deviation (Sn-1) determinedduring calibration to calculate the coefficient of variation (CV)for each dose value as follows:CV 5 100 3FSn21RG(4)

48、9.1.3 Document these coefficients of variation and note anythat are unusually large.NOTE 4In general, if the value of the coefficient of variation is greaterthan 62 %, then a re-determination of the data should be considered or, inthe extreme, the batch should be rejected.9.2 Effect of Absorbed Dose

49、 Rate:ISO/ASTM 51310:2004 (2012)(E)3 ISO/ASTM International 2017 All rights reserved 9.2.1 The shape (slope) of the calibration curve associatedwith some radiochromic optical waveguide dosimeters may beaffected by the absorbed dose rate for a given application. If anapplication requires an absorbed dose rate that is significantlydifferent from the absorbed dose rate used in cal