1、BRITISH STANDARD BS ISO 15572:1998 Guide for estimating uncertainties in dosimetry for radiation processing ICS 17.240BSISO15572:1998 This British Standard, having been prepared under the directionof the Engineering SectorCommittee, was publishedunder the authority ofthe Standards Committee andcomes
2、into effect on 15August1999 BSI 05-2000 ISBN 0 580 32910 0 National foreword This British Standard reproduces verbatim ISO15572:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee NCE/2, Health physics instrumentation, whic
3、h has the responsibility 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
4、 in the UK. A list 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 enti
5、tled “International 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. Complia
6、nce with a British 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 vi, pages 1 to 28, an inside back cover and abackcover. This standard has been updated
7、(see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO15572:1998 BSI 05-2000 i Contents Page National foreword Inside front cover Foreword iv Text of ISO 1
8、5572 1ii blankBSISO15572:1998 ii BSI 05-2000 Contents Page Foreword iv 1 Scope 1 2 Referenced Documents 1 3 Terminology 2 4 Significance and Use 5 5 Basic Concepts Components of Uncertainty 6 6 Evaluation of Standard Uncertainty 8 7 Sources of Uncertainty 11 8 Combining Uncertainties Statement of Un
9、certainty 13 9 Information Provided by Uncertainty 14 10 Keywords 14 Appendix X1 (nonmandatory information) Examples of uncertainty from calibration of dosimeters 15 Appendix X2 (nonmandatory information) Examples of uncertainty associated with measurement of dosimeter response 18 Appendix X3 (nonma
10、ndatory information) Examples of uncertainty associated with curve fitting 20 Appendix X4 (nonmandatory information) Uncertainty associated with routine use 25 Appendix X5 (nonmandatory information) Law of propagation of uncertainty (19) 27 References Inside back cover Figure 1 Graphical Illustratio
11、n of Value, Error, and Uncertainty 9 Figure 2 Graphical Illustration of Evaluating Type B Standard Uncertainty 11 Figure X2.1 Measured Specific Absorbance versus Wavelength for Red Perspex Dosimetry System 19 Figure X3.1 Response Curve for Optichromic Dosimetry System 21 Figure X3.2 Response Curve f
12、or Thin Film Radiochromic Dosimetry System 22 Figure X3.3 Response Curve for Red Perspex Dosimetry System Logarithmic 23 Figure X3.4 Response Curve for Red Perspex Dosimetry System 2 ndOrder Polynomial 23 Figure X3.5 Response Curve for Red Perspex Dosimetry System 3 rdOrder Polynomial 23 Figure X3.6
13、 Response Curve for Red Perspex Dosimetry System 4 thOrder Polynomial 24 Figure X3.7 Residuals for Red Perspex Dosimetry System 2 ndOrder Polynomial 24 Figure X3.8 Residuals for Red Perspex Dosimetry System 3 rdOrder Polynomial 25 Figure X4.1 Irradiation Temperature Dependence 26 Table 1 Examples of
14、 Uncertainty in Absorbed Dose Administered by a Gamma Ray Calibration Facility 12 Table 2 Examples of Uncertainty in Dosimeter Readings 12 Table 3 Examples of Uncertainty in Calibration Curve 12 Table 4 Examples of Uncertainty Due to Routine Use 12 Table X1.1 Example of Uncertainties in Absorbed Dos
15、e Values for a Pool Type Gamma Facility 15 Table X1.2 Example of Uncertainties in Absorbed Dose Values for Electron Beam Facility 15BSISO15572:1998 BSI 05-2000 iii Page Table X1.3 Example of Uncertainties in Absorbed Dose Values for Irradiation of Ceric-Cerous Dosimeters in a Gammacell 220 Irradiato
16、r Calibrated by Fricke Dosimetry 15 Table X1.4 Example of Uncertainties in Calibration of Ceric-Cerous Transfer Standard Dosimetry System 16 Table X1.5 Example of Uncertainties in Absorbed Dose Values Measured in a Production Irradiator Using Sets of Two Ceric-Cerous Dosimeters 16 Table X1.6 Example
17、 of Uncertainties in Calibration of Harwell Red 4034 Perspex Dosimeters in Production Irradiator Using Ceric-Cerous Transfer Standard Dosimeters 16 Table X1.7 Example of Overall Uncertainty for Calibration and Use of Red Perspex Dosimeters 17 Table X2.1 An Example of Type A Uncertainty in Specific A
18、bsorbance (Pooled Estimate) 18 Table X2.2 Measured Absorbance of Radiochromic Dosimeters Irradiated Under Reproducible Conditions 18 Table X2.3 Standard Deviations from Measurement of Absorbance 19 Table X3.1 Example of Dosimeter Response as a Function of Absorbed Dose for a Radiochromic Optical Wav
19、eguide Dosimetry System 20 Table X3.2 Curve Fit Data for Linear Fit to Radiochromic Optical Waveguide Dosimetry System 21 Table X3.3 Dosimeter Response as a Function of Absorbed Dose for a Thin Film Radiochromic Dosimetry System 21 Table X3.4 Logarithmic Transformed Linear Curve Fit Data for Thin Fi
20、lm Radiochromic System 22 Table X3.5 Dosimeter Response As a Function of Absorbed Dose for Red Perspex System 22 Table X3.6 Logarithmic Curve Fit Data for Red Perspex System 23 Table X3.7 Polynomial Fit Test Parameters 24BSISO15572:1998 iv BSI 05-2000 Foreword ISO (the International Organization for
21、 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
22、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 Inte
23、rnational 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 bodies casting a vote. International Standard ISO15572 was prepared by the American Society for Testing and
24、Materials (ASTM) Subcommittee E10.01 (as E1707-95) and wasadopted, under a special “fast-track procedure”, by Technical Committee ISO/TC85, Nuclear energy, in parallel with its approval by the ISO member bodies. A new ISO/TC85 Working Group WG 3, High-level dosimetry for radiation processing, was fo
25、rmed 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 ISO15572 is one of20 standards developed and published by ASTM. The20 fast-tracked standards and their associated ASTM
26、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 ceric-cerous sulfate dosimetry system 15556 E 1261-94 Guide for selection and calibration of dosimetr
27、y 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 15560 E 1400-95a Practice fo
28、r 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 in electron and bremsstrahlung irradiation facilities for food processing 15563 E 1538-93 Practice for
29、 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 system 15566 E 1607-94 Practice for use of the alanine-EPR dosimetry systemBSISO15572:1998 BSI 05-2000 v 15567 E 1608
30、-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 dosimeter calibrations 15569 E 1649-94 Practice for dosimetry in an electron-beam facility for radiatio
31、n processing at energies between300keV and25MeV 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 radiation processing 15572 E 1707-95 Guide for estimating uncertainties in dosimetry for radiation process
32、ing 15573 E 1818-96 Practice for dosimetry in an electron-beam facility for radiation processing at energies between80keV and300keV ISO Designation ASTM Designation Titlevi blankBSISO15572:1998 BSI 05-2000 1 1 Scope 1.1 This guide defines possible sources of error in dosimetry performed in gamma, x-
33、ray (bremsstrahlung) and electron irradiation facilities and offers procedures for estimating the resulting magnitude of the uncertainties in the measurement results. Basic concepts of measurement, estimate of the measured value of a quantity, “true” value, error and uncertainty are defined and disc
34、ussed. Components of uncertainty are discussed and methods are given for evaluating and estimating their values. How these contribute to the standard uncertainty in the reported values of absorbed dose are considered and methods are given for calculating the combined standard uncertainty and an esti
35、mate of overall (expanded) uncertainty. The methodology for evaluating components of uncertainty follows ISO procedures (see2.3). The traditional concepts of precision and bias are not used. Examples are given in five appendixes. 1.2 This guide assumes a working knowledge of statistics. Several stat
36、istical texts are included in the references (1, 2, 3, 4). 1) 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 approprite safety and health practices and determine the applica
37、bility of regulatory limitations prior to use. 2 Referenced Documents 2.1 ASTM Standards: E 170, Terminology Relating to Radiation Measurements and Dosimetry 2) . E 177, Practice for Use of the Terms Precision and Accuracy as Applied to Measurement of a Property of a Material 2) . E 178, Practice fo
38、r Dealing With Outlying Observations 2) . E 456, Terminology Relating to Quality and Statistics 3) . E 666, Practice for Calculating Absorbed Dose from Gamma or X Radiation 2) . E 876, Practice for Use of Statistics In the Evaluation of Spectrometric Data 4) . E 1026, Practice for Using the Fricke R
39、eference Standard Dosimetry System 2) . E 1204, Practice for Dosimetry in Gamma Irradiation Facilities for Food Processing 2) . E 1205, Practice for Use of a Ceric-Cerous Sulfate Dosimetry System 2) . E 1249, Practice for Minimizing Dosimetry Errors in Radiation Hardness Testing of Silicon Electroni
40、c Devices Using Co-60 Sources 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 Polymethylmethacrylate Dosimetry System 2) . E 1310, Practice for the
41、Use of a Radiochromic Optical Waveguide Dosimetry System 2) . E 1401, Practice for Use of a Dichromate Dosimetry System 2) . E 1431, Practice for Dosimetry in Electron and Bremsstrahlung Irradiation Facilities for Food Processing 2) . E 1607, Practice for Use of the Alanine-EPR Dosimetry System 2) .
42、 2.2 ICRU Reports: 5) ICRU Report 14, Radiation Dosimetry: X-Rays and Gamma Rays with Maximum Photon Energies Between 0.6 and 50MeV. ICRU Report 17, Radiation Dosimetry: X-Rays Generated at Potentials of5to150kV. ICRU Report 33, Radiation Quantities and Units. ICRU Report 34, The Dosimetry of Pulsed
43、 Radiation. ICRU Report 35, Radiation Dosimetry: Electron Beams with Energies Between 1 and50MeV. ICRU Report 37, Stopping Powers for Electrons and Positrons. 2.3 1) The boldface numbers in parentheses refer to a list of references at the end of this guide. 2) Annual Book of ASTM Standards, Vol 12.0
44、2. 3) Annual Book of ASTM Standards, Vol 14.02. 4) Annual Book of ASTM Standards, Vol 03.06. 5) Available from International Commission on Radiation Units and Measurements, 7910Woodmont Ave., Suite800 Bethesda, MD20814.BSISO15572:1998 2 BSI 05-2000 3 Terminology 3.1 Definitions 3.1.1 absorbed dose,
45、D quantity of radiation energy imparted per unit mass of a specified material. The unit of absorbed dose is the gray (Gy) where1 gray is equivalent to the absorption of1 joule per kilogram (=100rad). The mathematical relationship is the quotient of by dm, whereis the mean energy imparted by ionizing
46、 radiation to matter of mass dm (seeICRU33) D = /dm 3.1.2 accuracy of measurement closeness of the agreement between the result of a measurement and the true value of the measurand 3.1.3 calibration curve graphical representation of the relationship between dosimeter response and absorbed dose for a
47、 given dosimetry system. For a mathematical representation, see response function 3.1.4 coefficient of variation sample standard deviation expressed as a percentage of sample mean value (see3.37 and3.38) (CV) = S n1 / 100 % 3.1.5 combined standard uncertainty standard uncertainty of the result of a
48、measurement when that result is obtained from the values of a number of other quantities, equal to the positive square root of a sum of terms, the terms being the variances or covariances of these other quantities weighted according to how the measurement result varies with changes in these quantiti
49、es 3.1.6 confidence interval an interval estimate that contains the mean value of a parameter with a given probability 3.1.7 confidence level the probability that a confidence interval estimate contains the value of a parameter 3.1.8 corrected result result of a measurement after correction for the best estimate of systematic error 3.1.9 correction value that, added algebraically to the uncorrected result of a measurement, compensates for systematic error DISCUSSION The correction is eq
