ISO 11929-4:2022
电离辐射测量的特性极限（判定阈值、检测极限和覆盖间隔极限）的测定.基本原理和应用.第4部分:应用指南

Determination of the characteristic limits (decision threshold, detection limit and limits of the coverage interval) for measurements of ionizing radiation — Fundamentals and application — Part 4: Gui

标准号

ISO 11929-4:2022

发布

2022年

发布单位

国际标准化组织

当前最新

ISO 11929-4:2022

 

 

引用标准

ISO 11929-1 ISO 11929-2 ISO 3534-1 ISO 80000-1 ISO 80000-10 ISO/IEC Guide 98-3 ISO/IEC Guide 98-3:2008/Suppl.1 ISO/IEC Guide 98-3:2008/Suppl.2 ISO/IEC Guide 99

适用范围

This document specifies a procedure, in the field of ionizing radiation metrology, for the calculation of the “decision threshold”, the “detection limit” and the “limits of the coverage interval” for a non-negative ionizing radiation measurand when counting measurements with preselection of time or counts are carried out. The measurand results from a gross count rate and a background count rate as well as from further quantities on the basis of a model of the evaluation. In particular, the measurand can be the net count rate as the difference of the gross count rate and the background count rate, or the net activity of a sample. It can also be influenced by calibration of the measuring system, by sample treatment and by other factors. applications on the basis of the ISO/IEC Guide 98-3:2008/Suppl.1 in ISO 11929-2, applications to unfolding methods in ISO 11929-3, and guidance to the application in ISO 11929-4. radiation metrology. It is restricted to applications for which the uncertainties can be evaluated on the basis of the ISO/IEC Guide 98-3 (JCGM 2008). In ISO 11929-1:2019, Annex A the special case of repeated counting measurements with random influences and in ISO 11929-1:2019, Annex B, measurements with linear analogous ratemeters are covered. ISO/IEC Guide 98-3:2008/Suppl.1. ISO 11929-2 also presents some explanatory notes regarding general aspects of counting measurements and Bayesian statistics in measurements. spectrometric multi-channel measurements if evaluated by unfolding methods, in particular, alpha- and gamma-spectrometric measurements. Further, it provides some advice how to deal with correlations and covariances. procedure and then presenting a wide range of numerical examples. The examples cover elementary applications according to ISO 11929-1 and ISO 11929-2. 1 of the evaluation is involved. Further practical examples can be found in other International Standards, for example, see References [1 to 20]. NOTE A code system, named UncertRadio, is available allowing for calculations according to ISO 11929-1 www​ .thuenen​ .de/​ en/​ fi/​ fields​ -of​ -activity/​ marine​ -environment/​ coordination​ -centre​ -of​ -radioactivity/​ uncertradio/​ . The download contains a setup installation file that copies all files and folders into a folder specified by the user. After installation one has to add information to the PATH of Windows as indicated by a pop-up window during installation. English language can be chosen and extensive “help” information is available. Another tool is the package ‘metRology’[44] which is available for programming in R. It contains the two R functions ‘uncert’ and ‘uncertMC’ which perform the GUM-conform uncertainty propagation, either analytically or by the Monte Carlo method, respectively. Covariances/correlations of input quantities are included. Applying these two functions within iterations for decision threshold and the detection limit calculations simplifies the programming effort significantly. It is also possible to implement this document in a spreadsheet containing a Monte Carlo add-in or into other commercial mathematics software.

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