1、BRITISH STANDARD BS ISO 15570:1998 Practice for use of cellulose acetate dosimetry system ICS 17.240BSISO15570:1998 This British Standard, having been prepared under the directionof the Engineering SectorCommittee, was publishedunder the authority ofthe Standards Committee andcomes into effect on 15
2、 August 1999 BSI 04-2000 ISBN 0 580 32908 9 National foreword This British Standard reproduces verbatim ISO15570:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee NCE/2, Health physics instrumentation, which has the respo
3、nsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A l
4、ist of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “Internati
5、onal Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a Brit
6、ish Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pages ii to iv, pages 1 to 11 and a back cover. This standard has been updated (see copyright date) and may have h
7、ad amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO15570:1998 BSI 04-2000 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 15570 1ii blankBSISO15570:1998 ii B
8、SI 04-2000 Contents Page Foreword iii 1 Scope 1 2 Referenced Documents 1 3 Terminology 2 4 Significance and Use 3 5 Apparatus 3 6 Performance Check of Instrumentation 3 7 Preparation of Dosimeters 4 8 Calibration of Dosimeters 5 9 Condition for Practical Use 7 10 Report 8 11 Precision and Bias 8 12
9、Keywords 8 Appendix X1 (nonmandatory information) Information on cellulose acetate (CTA and CDA) dosimeters 9 Figure 1 Absorption Spectra Before and After Irradiation of Untinted Cellulose Triacetate (CTA) Film with a 2 MeV Electron Beam 4 Figure 2 The Relation Between the Increment of Absorbance %A
10、/Nominal Thickness (0.125 mm) at 280 nm and Dose in Untinted CTA by Electron and Gamma-Radiation 4 Figure 3 Absorption Spectra Before and After Irradiation to High Doses (Using 60 Co Rays, 0.4- and 10-MeV Electron Beams) of Yellow Cellulose Diacetate (CDA) Film 5 Figure 4 Increase in the Reciprocal
11、of Absorbance (I/A), at 390 nm Wavelength, as a Function of Absorbed Dose (in Water), when Yellow CDA is Irradiated with Electrons and Gamma Rays (16) 6 Table X1.1 Basic Properties of Available Dosimeters 9 Table X1.2 An Example of Single Purpose Absorbance Measuring Devices for Cellulose Acetate Do
12、simeters 9 References 10BSISO15570:1998 BSI 04-2000 iii 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
13、. 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 Intern
14、ational 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 least75% of the member bodi
15、es casting a vote. International Standard ISO15570 was prepared by the American Society for Testing and Materials (ASTM) Subcommittee E10.01 (as E1650-94) and was adopted, under a special “fast-track procedure”, by Technical Committee ISO/TC85, Nuclear energy, in parallel with its approval by the IS
16、O member bodies. A new ISO/TC85 Working Group WG3, High level dosimetry for radiation processing, was formed to review the voting comments from the ISO “Fast-track procedure” and to maintain these standards. The USA holds the convenership of this working group. International Standard ISO15570 is one
17、 of20standards developed and published by ASTM. The20fast-tracked standards and their associated ASTM designations are listed below: ISO Designation ASTM Designation Title 15554 E 1204-93 Practice for dosimetry in gamma irradiation facilities for food processing 15555 E 1205-93 Practice for use of a
18、 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
19、-94 Practice for use of a radiochromic optical waveguide dosimetry system 15560 E 1400-95a Practice for characterization and performance of a high-dose radiation dosimetry calibration laboratory 15561 E 1401-96 Practice for use of a dichromate dosimetry system 15562 E 1431-91 Practice for dosimetry
20、in electron and bremsstrahlung irradiation facilities for food processing 15563 E 1538-93 Practice for use of the ethanol-chlorobenzene dosimetry system 15564 E 1539-93 Guide for use of radiation-sensitive indicators 15565 E 1540-93 Practice for use of a radiochromic liquid dosimetry systemBSISO1557
21、0:1998 iv BSI 04-2000 15566 E 1607-94 Practice for use of the alanine-EPR dosimetry system 15567 E 1608-94 Practice for dosimetry in an X-ray (bremsstrahlung) facility for radiation processing 15568 E 1631-96 Practice for use of calorimetric dosimetry systems for electron beam dose measurements and
22、dosimeter calibrations 15569 E 1649-94 Practice for dosimetry in an electron-beam facility for radiation processing at energies between 300 keV and 25 MeV 15570 E 1650-94 Practice for use of cellulose acetate dosimetry system 15571 E 1702-95 Practice for dosimetry in a gamma irradiation facility for
23、 radiation processing 15572 E 1707-95 Guide for estimating uncertainties in dosimetry for radiation processing 15573 E 1818-96 Practice for dosimetry in an electron-beam facility for radiation processing at energies between 80 keV and 300 keV ISO Designation ASTM Designation TitleBSISO15570:1998 BSI
24、 04-2000 1 1 Scope 1.1 This practice covers the preparation, handling, testing and procedures for the use of cellulose acetate dosimetry systems, and the spectrometric, densitometric, or photometric readout equipment for measuring absorbed dose in materials irradiated by photons and electrons in ter
25、ms of absorbed dose in water. NOTE 1Cellulose acetate dosimeter refers to untinted and tinted cellulose triacetate (CTA) or cellulose diacetate (CDA) film dosimeter. 1.2 This practice applies to cellulose acetate film dosimeters that can be used within part or all of the specified ranges as follows:
26、 1.2.1 The absorbed dose range for untinted CTA and CDA is5 10 3to3 10 5Gy for photons and electrons, 1.2.2 The absorbed dose range for tinted CTA and CDA is 1 10 4 to1 10 6Gy for photons and electrons, 1.2.3 The absorbed dose rate for both CTA and CDA is from0.03to3 10 7Gy/s, 1.2.4 The radiation en
27、ergy range for photons is from0.1to50MeV, and 1.2.5 The radiation energy range for electrons is from0.2to50MeV. NOTE 2In cases where low-energy electrons and charged particles cannot completely penetrate the thickness of standard CTA and CDA films, thin films may be used (1, 2). 1) 1.2.6 The irradia
28、tion temperature range is from 10to70 C. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
29、 limitations prior to use. 2 Referenced Documents 2.1 ASTM Standards: E 170, Terminology Relating to Radiation Measurements and Dosimetry 2) . E 275, Practice for Describing and Measuring Performance of Ultraviolet, Visible, and Near Infrared Spectrophotometers 3) . E 666, Practice for Calculating A
30、bsorbed Dose from Gamma or X Radiation 2) . E 925, Practice for the Periodic Calibration of Narrow Band-Pass Spectrophotometers 3) . E 958, Practice for Measuring Practical Spectral Band-width of Ultraviolet-Visible Spectrophotometers 3) . E 1026, Practice for Using the Fricke Reference Standard Dos
31、imetry System 2) . E 1205, Practice for Use of a Ceric-Cerous Sulfate Dosimetry System 2) . E 1261, Guide for Selection and Calibration of Dosimetry Systems for Radiation Processing 2) . E 1275, Practice for Use of a Radiochromic Film Dosimetry System 2) . E 1276, Practice for Use of a Polymethlmeth
32、acrylate Dosimetry System 2) . E 1310, Practice for Use of a Radiochromic Optical Waveguide Dosimetry System 2) . E 1400, Practice for Characterization and Performance of a High-Dose Gamma Radiation Dosimetry Calibration Laboratory 2) . E 1401, Practice for Use of a Dichromate Dosimetry System 2) .
33、E 1538, Practice for Use of the Ethanol-Chlorobenzene Dosimetry System 2) . E 1540, Practice for Use of a Radiochromic Liquid Solution Dosimetry System 2) . E 1607, Practice for Use of the Alanine-EPR Dosimetry System 2) . E 1608, Practice for Dosimetry in an X-Ray (Bremsstrahlung) Irradiation Facil
34、ity for Radiation Processing 2) . E 1631, Practice for Use of Calorimetric Dosimetry Systems for Electron Beam Dose Measurements and Dosimeter Calibrations 2) . E 1649, Practice for Dosimetry in an Electron Beam Facility for Radiation Processing at Energies between 300 keV and 25 MeV. 2.2 Internatio
35、nal Commission on Radiation Units and Measurement (ICRU) Reports: 4) ICRU Report 14, Radiation Dosimetry: X-Rays and Gamma Rays with Maximum Photon Energies Between 0.6 and 50 MeV. ICRU Report 17, Radiation Dosimetry: X-Rays and Gamma Rays at Potentials of 5 to 150 kV. ICRU Report 33, Radiation Quan
36、tities and Units. 1) The boldface numbers in parentheses refer to the list of references at the end of this practice. 2) Annual Book of ASTM Standards, Vol 12.02. 3) Annual Book of ASTM Standards, Vol 03.06. 4) Available from International Commission on Radiation Units and Measurement, 7910 Woodmont
37、 Ave., Suite 800, Bethesda, MD 20814.BSISO15570:1998 2 BSI 04-2000 ICRU Report 34, The Dosimetry of Pulsed Radiation. ICRU Report 35, Radiation Dosimetry: Electron Beams with Energies Between 1 and 50 MeV. ICRU Report 37, Stopping Powers for Electrons and Positrons. ICRU Report 44, Tissue Substitute
38、s in Radiation Dosimetry and Measurement. 3 Terminology 3.1 absorbed dose, D quotient ofby dm, whereis the mean energy imparted by ionizing radiation to matter of mass dm (see Terminology E170 and ICRU Report33) the special name for the unit of absorbed dose is the gray (Gy): 1 Gy = 1 Jkg 1 formerly
39、, the special unit for absorbed dose was the rad: 1 rad = 10 2Jkg 1 3.2 absorbed dose mapping measurement of the absorbed-dose distribution in an irradiation unit through the use of dosimeters placed at specified locations throughout the product volume 3.3 analysis wavelength wavelength used in a sp
40、ectrophotometer, densitometer, or photometer for measuring optical absorbance 3.4 calibration curve graphical or mathematical relationship between dosimeter response and absorbed dose for a given dosimetry system; this term is also referred to as the response function 3.5 cellulose acetate dosimeter
41、 untinted and tinted cellulose triacetate (CTA) or cellulose diacetate (CDA) film dosimeters that undergo change in optical absorbance or optical density under ionizing radiation DISCUSSION This change in absorbance or optical density is related to radiation chemical change in cellulose acetate, pla
42、sticizer and tinted dyes, and can be related to absorbed dose in water. 3.6 dosimeter batch a quantity of dosimeters made from a specific mass of dosimetric material with uniform composition, fabricated in a single production run under controlled, consistent conditions, and having a unique identific
43、ation code 3.7 dosimetry system a system for determining absorbed dose, consisting of dosimeters, measurement instruments and their associated reference standards, and procedures for the systems use 3.8 electron equilibrium a condition that exists in a material under irradiation when the energies, n
44、umber, and direction of electrons induced by the radiation are constant throughout the volume of interest; thus, within such a volume, the sum of the energies of all electrons entering it is equal to the corresponding sum of all electrons leaving it 3.9 measurement quality assurance plan a documente
45、d program for the measurement process that quantities the total uncertainty of the measurements (both random and systematic error components); this plan shall demonstrate traceability to national standards, and shall show that the total uncertainty meets the requirements of the specific application
46、3.10 net absorbance, %A the difference between the optical absorbance of an unirradiated film dosimeter, A o , and the optical absorbance of an irradiated film dosimeter, A % A = A A o(for increasing absorbance) % A = A o A (for decreasing absorbance) 3.11 net optical density, %OD another expression
47、 for “net absorbance.” DISCUSSION This expression is more commonly used for film and plastic dosimeters than for liquid dosimeters. 3.12 specific net absorbance, k net absorbance, %A, at a selected wavelength divided by the optical path length, t, through the dosimeter (that is, film thickness) as f
48、ollows: k = %A/t de deBSISO15570:1998 BSI 04-2000 3 3.13 stock part of a dosimeter batch, held by the user 3.14 traceability the ability to show that a measurement is consistent with appropriate national or International Standards through an unbroken chain of comparisons 3.15 other appropriate terms
49、 may be found in Terminology E170 4 Significance and Use 4.1 The cellulose acetate (CTA and CDA) dosimetry systems provide a means of measuring absorbed dose in materials (317). Under the influence of radiation, chemical reactions take place in the cellulose acetate, plasticizer or dyes in the matrix, changing the optical absorption properties absorption wavelength (band) and density (18). Absorbance or optical density values are measured at the selected wavelength using a spectrophotometer, densitometer, or photometer. 4.2 In the use
