CEN ISO/TR 22930-1:2021

Evaluating the performance of continuous air monitors - Part 1: Air monitors based on accumulation sampling techniques (ISO/TR 22930-1:2020)

The use of a continuous air monitor (CAM) is mainly motivated by the need to be alerted quickly and in the most accurate way possible with an acceptable false alarm rate when a significant activity concentration value is exceeded, in order to take appropriate measures to reduce exposure of those involved.
The performance of this CAM does not only depend on the metrological aspect characterized by the decision threshold, the limit of detection and the measurement uncertainties but also on its dynamic capacity characterized by its response time as well as on the minimum detectable activity concentration corresponding to an acceptable false alarm rate.
The ideal performance is to have a minimum detectable activity concentration as low as possible associated with a very short response time, but unfortunately these two criteria are in opposition. It is therefore important that the CAM and the choice of the adjustment parameters and the alarm levels be in line with the radiation protection objectives.
The knowledge of a few factors is needed to interpret the response of a CAM and to select the appropriate CAM type and its operating parameters.
Among those factors, it is important to know the half-lives of the radionuclides involved, in order to select the appropriate detection system and its associated model of evaluation.
CAM using filter media accumulation sampling techniques are usually of two types:
a)    fixed filter;
b)    moving filter.
This document first describes the theory of operation of each CAM type i.e.:
—     the different models of evaluation considering short or long radionuclides half-lives values,
—     the dynamic behaviour and the determination of the response time.
In most case, CAM is used when radionuclides with important radiotoxicities are involved (small value of ALI). Those radionuclides have usually long half-life values.
Then the determination of the characteristic limits (decision threshold, detection limit, limits of the coverage interval) of a CAM is described by the use of long half-life models of evaluation.
Finally, a possible way to determine the minimum detectable activity concentration and the alarms setup is pointed out.
The annexes of this document show actual examples of CAM data which illustrate how to quantify the CAM performance by determining the response time, the characteristics limits, the minimum detectable activity concentration and the alarms setup.

Ermittlung der Leistungsfähigkeit kontinuierlicher Luftmonitore - Teil 1: Luftmonitore basierend auf Sammeltechnik mittels Anreicherung (ISO/TR 22930-1:2020)

Die Verwendung eines kontinuierlichen Luftmonitors (CAM, en: continuous air monitor) ist hauptsächlich darin begründet, bei der Überschreitung eines signifikanten Werts der Aktivitätskonzentration schnell und mit einer akzeptablen Fehlalarmrate möglichst genau alarmiert zu werden, um geeignete Maßnahmen zu ergreifen, um die Exposition der Beteiligten zu verringern.
Die Leistungsfähigkeit dieser kontinuierlichen Luftmonitore hängt nicht nur vom metrologischen Aspekt, der durch die Erkennungsgrenze, die Nachweisgrenze und die Messunsicherheiten charakterisiert ist, ab, son¬dern auch von der dynamischen Kapazität, die durch die Ansprechzeit charakterisiert ist, sowie von der kleinsten nachweisbaren Aktivitätskonzentration, die einer akzeptablen Fehlalarmrate entspricht.
Eine ideale Leistungsfähigkeit wäre eine möglichst geringe nachweisbare Aktivitätskonzentration, die mit einer sehr kurzen Ansprechzeit verbunden ist, jedoch stehen diese beiden Kriterien zueinander im Wider-spruch. Es ist daher wichtig, die kontinuierlichen Luftmonitore und die Wahl der Einstellparameter und Alarm¬schwellen in Einklang mit den Strahlenschutzzielen zu bringen.
Die Kenntnis einiger Faktoren ist notwendig, um das Ansprechen eines kontinuierlichen Luftmonitors zu inter¬pretieren und den geeigneten CAM-Typ und seine Betriebsparameter auszuwählen.
Bei diesen Faktoren ist es wichtig, die Halbwertszeiten der beteiligten Radionuklide zu kennen, um die geeig¬nete Erfassungseinrichtung und das dazugehörige Modell der Auswertung auszuwählen.
Kontinuierliche Luftmonitore, die Sammeltechniken mittels Anreicherung auf Filtermedien verwenden, werden üblicherweise in zwei Typen unterteilt:
a)   fest installierte Filter;
b)   bewegliche Filter.
Dieses Dokument beschreibt zunächst die Theorie des Betriebs der einzelnen CAM-Typen, z. B.:
–   die verschiedenen Modelle der Auswertung, wobei kurzlebige und langlebige Radionuklide betrachtet werden,
–   das dynamische Verhalten und die Ermittlung der Ansprechzeit.
In den meisten Fällen wird der kontinuierliche Luftmonitor verwendet, wenn Radionuklide mit bedeutender Radiotoxizität beteiligt sind (niedriger Grenzwert der Jahresaktivitätszufuhr, ALI). Diese Radionuklide haben üblicherweise eine lange Halbwertszeit.
Dann wird die Bestimmung der charakteristischen Grenzen (Erkennungsgrenze, Nachweisgrenze und Gren¬zen des Überdeckungsintervalls) eines kontinuierlichen Luftmonitors anhand der Modelle der Auswertung bei langen Halbwertszeiten beschrieben.
Schließlich wird ein möglicher Weg, die kleinste nachweisbare Aktivitätskonzentration und die Alarmein-stel¬lungen zu bestimmen, aufgezeigt.
Die Anhänge dieses Dokuments stellen aktuelle Beispiele von CAM-Daten dar, wie die Leistungsfähigkeit eines kontinuierlichen Luftmonitors anhand der Bestimmung der Ansprechzeit, der charakteristischen Gren¬zen, der kleinsten nachweisbaren Aktivitätskonzentration und der Alarmeinstellungen quantifiziert werden kann.

Évaluation des performances des dispositifs de surveillance de l'air en continu - Partie 1: Dispositifs de surveillance de l'air basés sur des techniques de prélèvement avec accumulation (ISO/TR 22930-1:2020)

L'utilisation d'un dispositif de surveillance de l'air en continu (CAM) est principalement motivée par la nécessité d'être alerté rapidement et de la façon la plus précise possible avec un taux acceptable de fausses alarmes lorsqu'une valeur d'activité volumique significative est dépassée, afin de prendre des mesures appropriées pour réduire l'exposition des personnes concernées.
Les performances de ce CAM dépendent non seulement de l'aspect métrologique caractérisé par le seuil de décision, la limite de détection et les incertitudes de mesure, mais aussi de sa capacité dynamique caractérisée par son temps de réponse ainsi que de l'activité volumique minimale détectable correspondant à un taux de fausses alarmes acceptable.
La situation idéale serait d'avoir une activité volumique minimale détectable aussi faible que possible et un temps de réponse associé très court, mais ces deux critères sont malheureusement en opposition. Il est donc important que le CAM et le choix des paramètres de réglage et des niveaux d'alarme soient alignés sur les objectifs de la radioprotection.
La connaissance de plusieurs facteurs est nécessaire pour interpréter la réponse d'un CAM et sélectionner le type de CAM adapté et ses paramètres de fonctionnement.
Parmi ces facteurs, il est important de connaître les demi-vies des radionucléides concernés, afin de sélectionner le système de détection approprié et son modèle d'évaluation associé.
Les CAM qui mettent en œuvre des techniques de prélèvement avec accumulation sont généralement de deux types:
a)    à support filtrant fixe;
b)    à support filtrant déroulant.
Le présent document décrit tout d'abord la théorie de fonctionnement de chaque type de CAM, à savoir:
—          les différents modèles d'évaluation en fonction de la demi-vie (courte ou longue) des radionucléides;
—          le comportement dynamique et la détermination du temps de réponse.
Dans la majorité des cas, un CAM est utilisé dans les situations impliquant des radionucléides à radiotoxicité importante (faible valeur LAI), qui ont généralement des demi-vies longues.
Le présent document décrit ensuite la détermination des limites caractéristiques (seuil de décision, limite de détection, limites de l'intervalle élargi) d'un CAM, en utilisant des modèles d'évaluation de demi-vies longues.
Il suggère enfin une méthode permettant de déterminer l'activité volumique minimale détectable et le paramétrage des alarmes.
Les annexes du présent document présentent des exemples actuels de données de CAM qui illustrent la quantification des performances d'un CAM en déterminant le temps de réponse, les limites caractéristiques, l'activité volumique minimale détectable et le paramétrage des alarmes.

Ugotavljanje zmogljivosti neprekinjeno delujočih zračnih nadzornikov - 1. del: Zračni nadzorniki na podlagi tehnik vzorčenja kopičenja zraka (ISO/TR 22930-1:2020)

General Information

• Status: Published
• Publication Date: 24-Aug-2021
• ICS: 13.280 - Radiation protection
• 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: 25-Aug-2021
• Due Date: 16-Sep-2022
• Completion Date: 25-Aug-2021
• Ref Project: SIST-TP CEN ISO/TR 22930-1:2021 - Evaluating the performance of continuous air monitors - Part 1: Air monitors based on accumulation sampling techniques (ISO/TR 22930-1:2020)

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2021
Ugotavljanje zmogljivosti neprekinjeno delujočih zračnih nadzornikov - 1. del:
Zračni nadzorniki na podlagi tehnik vzorčenja kopičenja zraka (ISO/TR 22930-
1:2020)
Evaluating the performance of continuous air monitors - Part 1: Air monitors based on
accumulation sampling techniques (ISO/TR 22930-1:2020)
Ermittlung der Leistungsfähigkeit kontinuierlicher Luftmonitore - Teil 1: Luftmonitore
basierend auf Sammeltechnik mittels Anreicherung (ISO/TR 22930-1:2020)
Évaluation des performances des dispositifs de surveillance de l'air en continu - Partie 1:
Dispositifs de surveillance de l'air basés sur des techniques de prélèvement avec
accumulation (ISO/TR 22930-1:2020)
Ta slovenski standard je istoveten z: CEN ISO/TR 22930-1:2021
ICS:
13.280 Varstvo pred sevanjem Radiation protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN ISO/TR 22930-1
TECHNICAL REPORT
RAPPORT TECHNIQUE
August 2021
TECHNISCHER BERICHT
ICS 13.280
English Version
Evaluating the performance of continuous air monitors -
Part 1: Air monitors based on accumulation sampling
techniques (ISO/TR 22930-1:2020)
Évaluation des performances des dispositifs de Ermittlung der Leistungsfähigkeit kontinuierlicher
surveillance de l'air en continu - Partie 1: Dispositifs de Luftmonitore - Teil 1: Luftmonitore basierend auf
surveillance de l'air basés sur des techniques de Sammeltechnik mittels Anreicherung (ISO/TR 22930-
prélèvement avec accumulation (ISO/TR 22930- 1:2020)
1:2020)
This Technical Report was approved by CEN on 16 August 2021. It has been drawn up by the Technical Committee CEN/TC 430.

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, Turkey 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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TR 22930-1:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO/TR 22930-1:2020 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 CEN ISO/TR 22930-1:2021 by Technical Committee
CEN/TC 430 “Nuclear energy, nuclear technologies, and radiological protection” the secretariat of
which is held by AFNOR.
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.
Endorsement notice
The text of ISO/TR 22930-1:2020 has been approved by CEN as CEN ISO/TR 22930-1:2021 without any
modification.
TECHNICAL ISO/TR
REPORT 22930-1
First edition
2020-05
Evaluating the performance of
continuous air monitors —
Part 1:
Air monitors based on accumulation
sampling techniques
Évaluation de la performance des dispositifs de surveillance de l'air
en continu —
Partie 1: Moniteurs d'air basés sur des techniques d'échantillonnage
par accumulation
Reference number
ISO/TR 22930-1:2020(E)
©
ISO 2020
ISO/TR 22930-1:2020(E)
© ISO 2020
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ii © ISO 2020 – All rights reserved

ISO/TR 22930-1:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Symbols . 4
5 Measuring principle . 6
6 Fixed-media filter monitor . 7
6.1 Preliminary note . 7
6.2 Study of the dynamic behaviour . 7
6.2.1 General. 7
6.2.2 Short half-life model of evaluation of the activity concentration . 8
6.2.3 Long half-life radionuclide activity concentration model of evaluation .11
6.2.4 Intermediate half-life radionuclide activity concentration model of evaluation .14
6.2.5 Comparison of the three fixed filter models of evaluation .15
7 Moving filter monitor .17
7.1 Preliminary note .17
7.2 Study of the dynamic behaviour .17
7.3 Activity concentration model of evaluation .20
8 Evaluation of the characteristic limits .23
8.1 General .23
8.2 Fixed media filter model of evaluation .24
8.2.1 General.24
8.2.2 Definition of the model .24
8.2.3 Standard uncertainty .24
8.2.4 Decision threshold.25
8.2.5 Detection limit .26
8.2.6 Limits of the coverage interval .26
8.3 Moving filter model of evaluation .28
8.3.1 Definition of the measurand .28
8.3.2 Standard uncertainty .28
8.3.3 Decision threshold.29
8.3.4 Detection limit .29
8.3.5 Limits of the coverage interval .29
9 Alarms setup, minimum detectable activity concentration and PME .29
Annex A (informative) Numerical example of gross beta emitting activity concentration
measurement on fixed filter .32
Annex B (informative) Numerical example of gross alpha emitting activity concentration
measurement on moving filter .37
Annex C (informative) Numerical example of iodine 131 activity concentration gamma
spectrometry measurement on fixed charcoal cartridge .41
Annex D (informative) Determination of the detectable activity concentration and its
associated response time by the use a linear regression and statistical test method .44
Bibliography .52
ISO/TR 22930-1:2020(E)
Foreword
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