EN ISO 11929-4:2023

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: Guidelines to applications (ISO 11929-4:2022)

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.
ISO 11929-4 gives guidance to the application of ISO 11929 (all parts), summarizing shortly the general procedure and then presenting a wide range of numerical examples. The examples cover elementary applications according to ISO 11929-1 and ISO 11929-2.

Bestimmung der charakteristischen Grenzen (Erkennungsgrenze, Nachweisgrenze und Grenzen des Überdeckungsintervalls) bei Messungen ionisierender Strahlung - Grundlagen und Anwendungen - Teil 4: Anwendungsleitfaden (ISO 11929-4:2022)

Dieses Dokument legt im Bereich der Metrologie ionisierender Strahlung ein Verfahren zur Berechnung der „Erkennungsgrenze“, der „Nachweisgrenze“ und der „Grenzen des Überdeckungsintervalls“ für eine nicht negative Messgröße der ionisierenden Strahlung bei Messungen mit Zeit- und Impulsvorwahl fest. Das Mess-ergebnis ergibt sich aus den Ergebnissen von Messungen einer Bruttozählrate und einer Nulleffektzählrate sowie weiteren Größen auf der Grundlage eines Modells der Auswertung. Insbesondere kann die Messgröße die Nettozählrate als Differenz der Bruttozählrate und der Nulleffektzählrate oder die Nettoaktivität einer Probe sein. Sie kann auch durch die Kalibrierung der Messeinrichtung, die Probenbehandlung und andere Faktoren beeinflusst sein.
ISO 11929 ist in vier Teile gegliedert: elementare Anwendungen in ISO 11929-1, fortgeschrittene Anwendun-gen auf der Grundlage von ISO/IEC Guide 98-3:2008/Supplement 1 in ISO 11929-2, Anwendungen auf Entfal-tungsverfahren in ISO 11929-3 und Anleitungen zur Anwendung in ISO 11929-4.
ISO 11929-1 behandelt elementare Anwendungen zählender Messungen, wie sie häufig im Bereich der Met-rologie ionisierender Strahlung vorkommen. Dieser Teil beschränkt sich auf Anwendungen, bei denen die Unsicherheiten auf der Grundlage des ISO/IEC Guide 98-3 (JCGM 2008) ermittelt werden können. In ISO 11929-1:2019, Anhang A, wird der spezielle Fall wiederholter zählender Messungen mit zufälligen Einflüs-sen und in ISO 11929-1:2019, Anhang B, Messungen mit linearen analogen Ratemetern behandelt.
ISO 11929-2 erweitert ISO 11929-1 auf die Auswertung von Messungen, bei denen die Messunsicherheiten nach ISO/IEC Guide 98-3:2008/Supplement 1 ermittelt werden. ISO 11929-2 enthält außerdem Erläuterungen zu allgemeinen Aspekten zählender Messungen und zur Anwendung der Bayes-Statistik auf Messungen.
ISO 11929-3 behandelt die Auswertung von Messungen mit Hilfe von Entfaltungsverfahren und zählende Viel-kanalmessungen, insofern diese mit Entfaltungsmethoden ausgewertet werden, insbesondere alpha- und gam-maspektrometrische Messungen. Außerdem gibt ISO 11929-3 Anleitungen, wie mit Korrelationen und Kovari-anzen zu verfahren ist.
ISO 11929-4 gibt nach einer kurzen Darstellung des Verfahrens mit einer Fülle von numerischen Beispielen Anleitungen zur Anwendung von ISO 11929 (alle Teile). Die Beispiele decken elementare Anwendungen nach ISO 11929-1 und ISO 11929-2 ab.
ISO 11929 (alle Teile) ist auch bei anderen Messungen gleich welcher Art anwendbar, wenn ein vergleichbares Modell der Auswertung angewendet wird. Weitere praktische Beispiele können in anderen internationalen Nor-men gefunden werden, siehe [1] bis [20].[...]

Détermination des limites caractéristiques (seuil de décision, limite de détection et limites de l'intervalle élargi) pour le mesurage des rayonnements ionisants - Principes fondamentaux et applications - Partie 4: Lignes directrices relatives aux applications (ISO 11929-4:2022)

Ugotavljanje karakterističnih mej (odločitveni prag, zaznavanje meje in omejitev intervala pokritja) pri meritvah ionizirnega sevanja - Osnove in uporaba - 4. del: Smernice za uporabo (ISO 11929-4:2022)

Ta dokument določa postopek na področju metrologije za ionizirno sevanje za izračun »odločitvenega praga«, »zaznavanja meje« in »omejitve intervala pokritja« za merjeno veličino ionizirnega sevanja, ki ni negativna, pri štetju meritev s predhodno izbranim časom ali štetji. Merjena veličina izhaja iz bruto hitrosti štetja in hitrosti štetja v ozadju ter iz dodatnih količin na podlagi modela vrednotenja. Merjena veličina je lahko predvsem neto hitrost štetja kot razlika med bruto hitrostjo štetja in hitrostjo štetja v ozadju oziroma neto aktivnost vzorca. Nanjo lahko vplivajo tudi umerjanje merilnega sistema, obdelava vzorca in drugi dejavniki.
Standard ISO 11929-4 podaja navodilo za način uporabe standarda ISO 11929 (vseh delov), pri čemer na kratko povzema splošni postopek in nato predstavlja širok nabor številčnih primerov. Primeri zajemajo elementarne načine uporabe skladno s standardi ISO 11929-1 in ISO 11929-2.

General Information

• Status: Published
• Publication Date: 18-Jul-2023
• ICS: 17.240 - Radiation measurements
• Technical Committee: CEN/TC 430 - Nuclear energy, nuclear technologies, and radiological protection
• Drafting Committee: CEN/TC 430 - Nuclear energy, nuclear technologies, and radiological protection
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 19-Jul-2023
• Due Date: 26-Apr-2025
• Completion Date: 19-Jul-2023
• Ref Project: SIST EN ISO 11929-4:2023 - 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: Guidelines to applications (ISO 11929-4:2022)

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2023
Ugotavljanje karakterističnih mej (odločitveni prag, zaznavanje meje in omejitev
intervala pokritja) pri meritvah ionizirnega sevanja - Osnove in uporaba - 4. del:
Smernice za uporabo (ISO 11929-4:2022)
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: Guidelines to applications (ISO 11929-4:2022)
Détermination des limites caractéristiques (seuil de décision, limite de détection et limites
de l'intervalle élargi) pour le mesurage des rayonnements ionisants - Principes
fondamentaux et applications - Partie 4: Lignes directrices relatives aux applications
(ISO 11929-4:2022)
Ta slovenski standard je istoveten z: EN ISO 11929-4:2023
ICS:
17.240 Merjenje sevanja Radiation measurements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11929-4
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2023
EUROPÄISCHE NORM
ICS 17.240
English Version
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: Guidelines to
applications (ISO 11929-4:2022)
Détermination des limites caractéristiques (seuil de
décision, limite de détection et limites de l'intervalle
élargi) pour le mesurage des rayonnements ionisants -
Principes fondamentaux et applications - Partie 4:
Lignes directrices relatives aux applications (ISO
11929-4:2022)
This European Standard was approved by CEN on 16 July 2023.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11929-4:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 11929-4:2022 has been prepared by Technical Committee ISO/TC 85 "Nuclear energy,
nuclear technologies, and radiological protection” of the International Organization for Standardization
(ISO) and has been taken over as EN ISO 11929-4:2023 by Technical Committee CEN/TC 430 “Nuclear
energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2024, and conflicting national standards shall
be withdrawn at the latest by January 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 11929-4:2022 has been approved by CEN as EN ISO 11929-4:2023 without any
modification.
INTERNATIONAL ISO
STANDARD 11929-4
Third edition
2022-07
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:
Guidelines to applications
Détermination des limites caractéristiques (seuil de décision, limite
de détection et limites de l'intervalle élargi) pour le mesurage des
rayonnements ionisants — Principes fondamentaux et applications —
Partie 4: Lignes directrices relatives aux applications
Reference number
ISO 11929-4:2022(E)
ISO 11929-4:2022(E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 11929-4:2022(E)
Contents Page
Foreword .vii
Introduction .viii
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Quantities and symbols . 3
5 Summary of this document .5
5.1 Procedures according to ISO 11929 (all parts) . 5
5.2 Survey on the examples . 5
5.3 General stipulations . 8
6 Counting measurements with small or moderate uncertainties .9
6.1 Definition of the task and general aspects . 9
6.2 Model of evaluation and standard uncertainty . 9
6.3 Available information, input data, and specifications . 9
6.4 Evaluation of the measurement and characteristic limits according to ISO 11929-1 . 10
6.4.1 Background effect . 10
6.4.2 Primary result and its associated standard uncertainty . . 10
6.4.3 Standard uncertainty as a function of an assumed true value . 10
6.4.4 Decision threshold . 10
6.4.5 Detection limit . 11
6.4.6 Limits of coverage intervals . 11
6.4.7 The best estimate and its associated standard uncertainty . 11
6.5 Documentation of the results obtained by ISO 11929-1 and ISO 11929-2 . 11
6.6 Assessment and explanations . 13
7 Counting measurement with small count numbers .14
7.1 Definition of the task and general aspects . 14
7.2 Model of evaluation and standard uncertainty . 14
7.3 Available information, input data, and specifications . 14
7.4 Evaluation of the measurement and characteristic limits according to ISO 11929-1 .15
7.4.1 Background effect . 15
7.4.2 Primary result and its associated standard uncertainty . .15
7.4.3 Standard uncertainty as a function of an assumed true value . 16
7.4.4 Decision threshold . 16
7.4.5 Detection limit . 16
7.4.6 Limits of coverage intervals . 17
7.4.7 The best estimate and its associated standard uncertainty . 17
7.5 Documentation of the results obtained by ISO 11929-1 and ISO 11929-2 . 17
7.6 Assessment and explanations . 18
7.7 An alternative example of a measurement with small count numbers . 19
7.7.1 General . 19
7.7.2 Background effect . 20
7.7.3 Primary result and its associated standard uncertainty . .20
7.7.4 Standard uncertainty as a function of an assumed true value .20
7.7.5 Decision threshold .20
7.7.6 Detection limit . 21
7.7.7 Limits of coverage intervals . 21
7.7.8 The best estimate and its associated standard uncertainty . 21
7.8 Documentation of the results obtained by ISO 11929-1 and ISO 11929-2 .22
7.9 Assessment of the alternative example and explanations.
...