1、 IEC TR 62461 Edition 2.0 2015-01 TECHNICAL REPORT Radiation protection instrumentation Determination of uncertainty in measurement IEC TR 62461:2015-01(en) colour inside THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2015 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified,
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10、ch/csc If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csciec.ch. IEC TR 62461 Edition 2.0 2015-01 TECHNICAL REPORT Radiation protection instrumentation Determination of uncertainty in measurement INTERNATIONAL ELECTRO
11、TECHNICAL COMMISSION ICS 13.280 ISBN 978-2-8322-2216-4 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. colour inside 2 IEC TR 62461:2015 IEC 2015 CONTENTS FOREWORD . 5 INTRODUCTION . 7 1 Scope
12、 8 2 Normative references 8 3 Terms and definitions 9 4 List of symbols 12 5 The GUM and the GUM S1 concept . 14 5.1 General concept of uncertainty determination . 14 5.1.1 Overview in four steps . 14 5.1.2 Summary of the analytical method for steps 3 and 4 15 5.1.3 Summary of the Monte Carlo method
13、 for steps 3 and 4 15 5.1.4 Which method to use: Analytical or Monte Carlo? 16 5.2 Example of a model function . 16 5.3 Collection of data and existing knowledge for the example 18 5.3.1 General . 18 5.3.2 Calibration factor for the example 19 5.3.3 Zero reading for the example . 20 5.3.4 Reading fo
14、r the example 21 5.3.5 Relative response or correction factor for the example 21 5.3.6 Comparison of probability density distributions for input quantities 23 5.4 Calculation of the result of a measurement and its standard uncertainty (uncertainty budget) 25 5.4.1 General . 25 5.4.2 Analytical metho
15、d 25 5.4.3 Monte Carlo method 26 5.4.4 Uncertainty budgets . 26 5.5 Statement of the measurement result and its expanded uncertainty 27 5.5.1 General . 27 5.5.2 Analytical method 28 5.5.3 Monte Carlo method 28 5.5.4 Representation of the output distribution function in a simple form (Monte Carlo met
16、hod) 31 6 Results below the decision threshold of the measuring device . 31 7 Overview of the annexes . 32 Annex A (informative) Example of an uncertainty analysis for a measurement with an electronic ambient dose equivalent rate meter according to IEC 60846-1:2009 . 33 A.1 General . 33 A.2 Model fu
17、nction 33 A.3 Calculation of the complete result of the measurement (measured value, probability density distribution, associated standard uncertainty, and the coverage interval) . 34 A.3.1 General . 34 A.3.2 Low level of consideration of measuring conditions 35 A.3.3 High level of consideration of
18、measuring conditions . 37 Annex B (informative) Example of an uncertainty analysis for a measurement with a passive integrating dosimetry system according to IEC 62387:2012 40 IEC TR 62461:2015 IEC 2015 3 B.1 General . 40 B.2 Model function 40 B.3 Calculation of the complete result of the measuremen
19、t (measured value, probability density distribution, associated standard uncertainty, and the coverage interval) . 41 B.3.1 General . 41 B.3.2 Low level of consideration of workplace conditions 41 B.3.3 High level of consideration of workplace conditions . 43 Annex C (informative) Example of an unce
20、rtainty analysis for a measurement with an electronic direct reading neutron ambient dose equivalent meter according to IEC 61005:2003 46 C.1 General . 46 C.2 Model function 46 C.3 Calculation of the complete result of the measurement (measured value, probability density distribution, associated sta
21、ndard uncertainty, and the coverage interval) . 47 C.3.1 General . 47 C.3.2 Analytical method 47 C.3.3 Monte Carlo method 48 C.3.4 Comparison of the result of the analytical and the Monte Carlo method . 49 Annex D (informative) Example of an uncertainty analysis for a calibration of radon activity m
22、onitor according to the IEC 61577 series 51 D.1 General . 51 D.2 Model function 51 D.3 Calculation of the complete result of the measurement (measured value, probability density distribution, associated standard uncertainty, and the coverage interval) . 51 Annex E (informative) Example of an uncerta
23、inty analysis for a measurement of surface emission rate with a contamination meter according to IEC 60325:2002 . 54 E.1 General . 54 E.2 Model function 54 E.3 Calculation of the complete result of the measurement (measured value, probability density distribution, associated standard uncertainty, an
24、d the coverage interval) . 54 E.3.1 General . 54 E.3.2 Effects of distance . 55 E.3.3 Contamination non-uniformity 55 E.3.4 Surface absorption 56 E.3.5 Other influence quantities 56 E.3.6 Uncertainty budget 56 Bibliography 59 Figure 1 Triangular probability density distribution of possible values n
25、for the calibration factor N 20 Figure 2 Rectangular probability density distribution of possible values g 0 for the zero reading G 021 Figure 3 Gaussian probability density distribution of possible values g for the reading G 21 Figure 4 Comparison of different probability density distributions of p
26、ossible values: rectangular (broken line), triangular (dotted line) and Gaussian (solid line) distribution . 24 Figure 5 Distribution function Q of the measured value 29 4 IEC TR 62461:2015 IEC 2015 Figure 6 Probability density distribution (PDF) of the measured value 30 Figure C.1 Results of the an
27、alytical (red dashed lines) and the Monte Carlo method (grey histogram and blue dotted and solid lines) for ) 10 ( * H . 50 Figure D.1 Result of the analytical (red dashed lines) and the Monte Carlo method (grey histogram and blue dotted lines) for K T53 Table 1 Symbols (and abbreviated terms) used
28、in the main text (excluding annexes) 12 Table 2 Standard uncertainty and method to compute the probability density distributions shown in Figure 4 24 Table 3 Example of an uncertainty budget for a measurement with an electronic dosemeter using the model function M = N K (G G 0 ) and low level of con
29、sideration of the workplace conditions, see 5.3.5.2 . 27 Table 4 Example of an uncertainty budget for a measurement with an electronic dosemeter using the model function M = N K (G G 0 ) and high level of consideration of the workplace conditions, see 5.3.5.3 . 27 Table A.1 Example of an uncertainty
30、 budget for a dose rate measurement according to IEC 60846-1:2009 with an instrument having a logarithmic scale and low level of consideration of the measuring conditions, see text for details 36 Table A.2 Example of an uncertainty budget for a dose rate measurement according to IEC 60846-1:2009 wit
31、h an instrument having a logarithmic scale and high level of consideration of the measuring conditions, see text for details 38 Table B.1 Example of an uncertainty budget for a photon dose measurement with a passive dosimetry system according to IEC 62387-1:2007 and low level of consideration of the
32、 workplace conditions, see text for details 42 Table B.2 Example of an uncertainty budget for a photon dose measurement with a passive dosimetry system according to IEC 62387-1:2007 and high level of consideration of the measuring conditions, see text for details 44 Table C.1 Example of an uncertain
33、ty budget for a neutron dose measurement according to IEC 61005:2003 using the analytical method. 48 Table C.2 Example of an uncertainty budget for a neutron dose rate measurement according to IEC 61005:2003 using the Monte Carlo method 49 Table C.3 Results of the analytical and the Monte Carlo meth
34、od 50 Table D.1 List of quantities used in formula (D.1) . 51 Table D.2 List of data available for the input quantities of formula (D.1) . 52 Table D.3 Example of an uncertainty budget for the calibration of a radon monitor according to IEC 61577, see text for details 52 Table E.1 Example of an unce
35、rtainty budget for a surface emission rate measurement according to IEC 60325:2002, see text for details . 57 Table E.2 Example of an uncertainty budget for a surface emission rate measurement according to IEC 60325:2002 for the determination of the uncertainty at a measured value of zero 58 IEC TR
36、62461:2015 IEC 2015 5 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ RADIATION PROTECTION INSTRUMENTATION DETERMINATION OF UNCERTAINTY IN MEASUREMENT FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical
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48、 example “state of the art“. IEC 62461, which is a technical report, has been prepared by subcommittee 45B: Radiation protection instrumentation, of IEC technical committee 45: Nuclear instrumentation. This second edition of IEC TR 62461 cancels and replaces the first edition, published in 2006, and
49、 constitutes a technical revision. The main changes with respect to the previous edition are as follows: add to the analytical method for the determination of uncertainty the Monte Carlo method for the determination of uncertainty according to supplement 1 of the Guide to the Expression of uncertainty in measurement (GUM S1), and add a very simple method to judge whether a measured result is significantly different from zero or not based on ISO 11929. 6 IEC TR 62461:2015 IEC 20
