Measurement of radioactivity in the environment - Air: radon-222 - Part 2: Integrated measurement method for determining average potential alpha energy concentration of its short-lived decay products (ISO 11665-2:2019)

This document describes integrated measurement methods for short-lived radon‑222 decay products[4]. It gives indications for measuring the average potential alpha energy concentration of short‑lived radon-222 decay products in the air and the conditions of use for the measuring devices.
This document covers samples taken over periods varying from a few weeks to one year. This document is not applicable to systems with a maximum sampling duration of less than one week.
The measurement method described is applicable to air samples with potential alpha energy concentration of short-lived radon-222 decay products greater than 10 nJ/m3 and lower than 1 000 nJ/m3.
NOTE       For informative purposes only, this document also addresses the case of radon-220 decay products, given the similarity in behaviour of the radon isotopes 222 and 220.

Ermittlung der Radioaktivität in der Umwelt - Luft: Radon-222 - Teil 2: Integrierendes Messverfahren für die Bestimmung des Durchschnittswertes der potenziellen Alpha-Energiekonzentration der kurzlebigen Radon-Folgeprodukte (ISO 11665-2:2019)

Dieses Dokument beschreibt integrierende Messverfahren für kurzlebige 222Rn-Folgeprodukte [4]. Es gibt Hinweise für die Bestimmung des Durchschnittswerts der potenziellen Alpha-Energiekonzentration der kurz-lebigen 222Rn-Folgeprodukte in der Luft und für die Bedingungen zum Einsatz der Messgeräte.
Dieses Dokument beinhaltet die Probenahme während Zeiträumen, die von wenigen Wochen bis zu einem Jahr variieren. Dieses Dokument ist nicht anwendbar auf Messsysteme mit einer maximalen Dauer der Pro-benahme von weniger als einer Woche.
Das hier beschriebene Messverfahren ist anwendbar für Luftproben mit einer potenziellen Alpha-Energiekon-zentration der kurzlebigen 222Rn-Folgeprodukte von über 10 nJ m–3 und unter 1 000 nJ m–3.
ANMERKUNG   Zur Information behandelt dieses Dokument auch den Fall von 220Rn-Folgeprodukten und zeigt die Ähnlichkeit im Verhalten der Radonisotope 222 und 220.

Mesurage de la radioactivité dans l'environnement - Air: radon 222 - Partie 2: Méthode de mesure intégrée pour la détermination de l'énergie alpha potentielle volumique moyenne de ses descendants à vie courte (ISO 11665-2:2019)

Le présent document décrit les méthodes de mesure intégrée pour les descendants à vie courte du radon 222[4]. Elle donne des indications pour mesurer l'énergie alpha potentielle volumique moyenne des descendants à vie courte du radon 222 dans l'air et sur les conditions d'utilisation des dispositifs de mesure.
Le présent document concerne des échantillons prélevés sur des périodes allant de quelques semaines à un an. Le présent document ne s'applique pas aux systèmes dont la durée de prélèvement maximale est inférieure à une semaine.
La méthode de mesure décrite s'applique aux échantillons d'air ayant une énergie alpha potentielle volumique des descendants à vie courte du radon 222 supérieure à 10 nJ/m3 et inférieure 1 000 nJ/m3.
NOTE       À titre informatif uniquement, le présent document traite également le cas des descendants du radon 220 en raison de la similitude de comportement des isotopes 222 et 220 du radon.

Merjenje radioaktivnosti v okolju - Zrak: radon Rn-222 - 2. del: Integrirana merilna metoda za ugotavljanje povprečne potencialne koncentracije alfa energije njegovih kratkoživih razpadnih produktov (ISO 11665-2:2019)

Ta dokument opisuje integrirane merilne metode za kratkožive razpadne produkte radona-222[4]. Podaja navedbe za merjenje povprečne potencialne koncentracije alfa energije kratkoživih razpadnih produktov radona-222 v zraku in pogoje uporabe za merilne naprave. Ta dokument obravnava vzorce, odvzete v obdobjih vse od nekaj tednov do enega leta. Ta dokument se ne uporablja za sisteme z najdaljšim obdobjem vzorčenja manj kot en teden. Opisana merilna metoda se uporablja za vzorce zraka s potencialno koncentracijo alfa energije kratkoživih razpadni produktov radona-222, ki so večji od 10 nJ/m3 in manjši od 1000 nJ/m3.

General Information

Status
Published
Publication Date
15-Oct-2019
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
16-Oct-2019
Completion Date
16-Oct-2019

RELATIONS

Buy Standard

Standard
EN ISO 11665-2:2020
English language
21 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN ISO 11665-2:2020
01-januar-2020
Nadomešča:
SIST EN ISO 11665-2:2015

Merjenje radioaktivnosti v okolju - Zrak: radon Rn-222 - 2. del: Integrirana merilna

metoda za ugotavljanje povprečne potencialne koncentracije alfa energije
njegovih kratkoživih razpadnih produktov (ISO 11665-2:2019)

Measurement of radioactivity in the environment - Air: radon-222 - Part 2: Integrated

measurement method for determining average potential alpha energy concentration of its

short-lived decay products (ISO 11665-2:2019)

Ermittlung der Radioaktivität in der Umwelt - Luft: Radon-222 - Teil 2: Integrierendes

Messverfahren für die Bestimmung des Durchschnittswertes der potenziellen Alpha-

Energiekonzentration der kurzlebigen Radon-Folgeprodukte (ISO 11665-2:2019)

Mesurage de la radioactivité dans l'environnement - Air: radon 222 - Partie 2: Méthode

de mesure intégrée pour la détermination de l'énergie alpha potentielle volumique

moyenne de ses descendants à vie courte (ISO 11665-2:2019)
Ta slovenski standard je istoveten z: EN ISO 11665-2:2019
ICS:
13.040.99 Drugi standardi v zvezi s Other standards related to air
kakovostjo zraka quality
17.240 Merjenje sevanja Radiation measurements
SIST EN ISO 11665-2:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN ISO 11665-2:2020
---------------------- Page: 2 ----------------------
SIST EN ISO 11665-2:2020
EN ISO 11665-2
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2019
EUROPÄISCHE NORM
ICS 13.040.01; 17.240 Supersedes EN ISO 11665-2:2015
English Version
Measurement of radioactivity in the environment - Air:
radon-222 - Part 2: Integrated measurement method for
determining average potential alpha energy concentration
of its short-lived decay products (ISO 11665-2:2019)

Mesurage de la radioactivité dans l'environnement - Ermittlung der Radioaktivität in der Umwelt - Luft:

Air: radon 222 - Partie 2: Méthode de mesure intégrée Radon-222 - Teil 2: Integrierendes Messverfahren für

pour la détermination de l'énergie alpha potentielle die Bestimmung des Durchschnittswertes der

volumique moyenne de ses descendants à vie courte potenziellen Alpha-Energiekonzentration der

(ISO 11665-2:2019) kurzlebigen Radon-Folgeprodukte (ISO 11665-
2:2019)
This European Standard was approved by CEN on 6 September 2019.

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, 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

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11665-2:2019 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 11665-2:2020
EN ISO 11665-2:2019 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

---------------------- Page: 4 ----------------------
SIST EN ISO 11665-2:2020
EN ISO 11665-2:2019 (E)
European foreword

This document (EN ISO 11665-2:2019) has been prepared by Technical Committee ISO/TC 85 "Nuclear

energy, nuclear technologies, and radiological protection" in collaboration with 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 April 2020, and conflicting national standards shall be

withdrawn at the latest by April 2020.

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.

This document supersedes EN ISO 11665-2:2015.

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, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 11665-2:2019 has been approved by CEN as EN ISO 11665-2:2019 without any

modification.
---------------------- Page: 5 ----------------------
SIST EN ISO 11665-2:2020
---------------------- Page: 6 ----------------------
SIST EN ISO 11665-2:2020
INTERNATIONAL ISO
STANDARD 11665-2
Second edition
2019-09
Measurement of radioactivity in the
environment — Air: radon-222 —
Part 2:
Integrated measurement method for
determining average potential alpha
energy concentration of its short-lived
decay products
Mesurage de la radioactivité dans l'environnement — Air: radon 222 —
Partie 2: Méthode de mesure intégrée pour la détermination de
l'énergie alpha potentielle volumique moyenne de ses descendants à
vie courte
Reference number
ISO 11665-2:2019(E)
ISO 2019
---------------------- Page: 7 ----------------------
SIST EN ISO 11665-2:2020
ISO 11665-2:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 11665-2:2020
ISO 11665-2:2019(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms, definitions and symbols ............................................................................................................................................................ 1

3.1 Terms and definitions ....................................................................................................................................................................... 1

3.2 Symbols ......................................................................................................................................................................................................... 2

4 Principle ........................................................................................................................................................................................................................ 3

5 Equipment ................................................................................................................................................................................................................... 3

5.1 General ........................................................................................................................................................................................................... 3

5.2 Measuring device .................................................................................................................................................................................. 3

5.2.1 Sampling system .............................................................................................................................................................. 3

5.2.2 Detection system.............................................................................................................................................................. 3

5.3 Counting system .................................................................................................................................................................................... 4

6 Sampling ........................................................................................................................................................................................................................ 4

6.1 Sampling objective ............................................................................................................................................................................... 4

6.2 Sampling characteristics ......... ........................................................................................................................................................ 4

6.3 Sampling conditions ........................................................................................................................................................................... 5

6.3.1 General...................................................................................................................................................................................... 5

6.3.2 Installation of sampling system .......................................................................................................................... 5

6.3.3 Sampling duration .......................................................................................................................................................... 5

6.3.4 Volume of air sampled .................. ......................................................................................................................... ...... 5

7 Detection method ................................................................................................................................................................................................ 6

8 Measurement ........................................................................................................................................................................................................... 6

8.1 Procedure .................................................................................................................................................................................................... 6

8.2 Influence quantities ............................................................................................................................................................................ 6

8.3 Calibration .................................................................................................................................................................................................. 7

9 Expression of results ........................................................................................................................................................................................ 7

9.1 Average potential alpha energy concentration ........................................................................................................... 7

9.2 Standard uncertainty ......................................................................................................................................................................... 8

9.3 Decision threshold and detection limit .............................................................................................................................. 9

9.4 Limits of the confidence interval ............................................................................................................................................. 9

10 Test report ................................................................................................................................................................................................................... 9

Annex A (informative) Example of a method meeting the requirements of this document ....................11

Bibliography .............................................................................................................................................................................................................................13

© ISO 2019 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 11665-2:2020
ISO 11665-2:2019(E)
Foreword

ISO (the International Organization for 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 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.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 85, Nuclear energy, nuclear technologies,

and radiological protection, Subcommittee SC 2, Radiological protection.

This second edition cancels and replaces the first edition (ISO 11665-2:2012), of which it constitutes a

minor revision. The changes compared to the previous edition are as follows:
— update of the Introduction;
— update of the Bibliography.
A list of all the parts in the ISO 11665 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 11665-2:2020
ISO 11665-2:2019(E)
Introduction

Radon isotopes 222, 219 and 220 are radioactive gases produced by the disintegration of radium

isotopes 226, 223 and 224, which are decay products of uranium-238, uranium-235 and thorium-232

respectively, and are all found in the earth's crust (see Annex A for further information). Solid elements,

[1]
also radioactive, followed by stable lead are produced by radon disintegration .

When disintegrating, radon emits alpha particles and generates solid decay products, which are also

radioactive (polonium, bismuth, lead, etc.). The potential effects on human health of radon lie in its solid

decay products rather than the gas itself. Whether or not they are attached to atmospheric aerosols,

radon decay products can be inhaled and deposited in the bronchopulmonary tree to varying depths

[2][3][4][5]
according to their size
[6]

Radon is today considered to be the main source of human exposure to natural radiation. UNSCEAR

suggests that, at the worldwide level, radon accounts for around 52 % of global average exposure

to natural radiation. The radiological impact of isotope 222 (48 %) is far more significant than

isotope 220 (4 %), while isotope 219 is considered negligible (see Annex A). For this reason, references

to radon in this document refer only to radon-222.

Radon activity concentration can vary from one to more orders of magnitude over time and space.

Exposure to radon and its decay products varies tremendously from one area to another, as it depends

on the amount of radon emitted by the soil and building materials, weather conditions, and on the

degree of containment in the areas where individuals are exposed.

As radon tends to concentrate in enclosed spaces like houses, the main part of the population exposure

is due to indoor radon. Soil gas is recognized as the most important source of residential radon through

infiltration pathways. Other sources are described in other parts of ISO 11665 and ISO 13164 series for

[58].
water

Radon enters into buildings via diffusion mechanism caused by the all-time existing difference between

radon activity concentrations in the underlying soil and inside the building, and via convection

mechanism inconstantly generated by a difference in pressure between the air in the building and the

air contained in the underlying soil. Indoor radon activity concentration depends on radon activity

concentration in the underlying soil, the building structure, the equipment (chimney, ventilation

systems, among others), the environmental parameters of the building (temperature, pressure, etc.)

and the occupants’ lifestyle.

To limit the risk to individuals, a national reference level of 100 Bq·m is recommended by the World

[5] -3

Health Organization . Wherever this is not possible, this reference level should not exceed 300 Bq·m .

This recommendation was endorsed by the European Community Member States that shall establish

national reference levels for indoor radon activity concentrations. The reference levels for the annual

−3[5]
average activity concentration in air shall not be higher than 300 Bq·m .

To reduce the risk to the overall population, building codes should be implemented that require radon

prevention measures in buildings under construction and radon mitigating measures in existing

buildings. Radon measurements are needed because building codes alone cannot guarantee that radon

concentrations are below the reference level.

Variations of a few nanojoules per cubic metre to several thousand nanojoules per cubic metre are

observed in the potential alpha energy concentration of short-lived radon decay products.

The potential alpha energy concentration of short-lived radon-222 decay products in the atmosphere

can be measured by spot and integrated measurement methods (see ISO 11665-1). This document deals

with integrated measurement methods. Integrated measuring methods are applicable in assessing

[4]
human exposure to radiation .

NOTE The origin of radon-222 and its short-lived decay products in the atmospheric environment and other

measurement methods are described generally in ISO 11665-1.
© ISO 2019 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 11665-2:2020
---------------------- Page: 12 ----------------------
SIST EN ISO 11665-2:2020
INTERNATIONAL STANDARD ISO 11665-2:2019(E)
Measurement of radioactivity in the environment — Air:
radon-222 —
Part 2:
Integrated measurement method for determining average
potential alpha energy concentration of its short-lived
decay products
1 Scope
[4]

This document describes integrated measurement methods for short-lived radon-222 decay products .

It gives indications for measuring the average potential alpha energy concentration of short-lived

radon-222 decay products in the air and the conditions of use for the measuring devices.

This document covers samples taken over periods varying from a few weeks to one year. This document

is not applicable to systems with a maximum sampling duration of less than one week.

The measurement method described is applicable to air samples with potential alpha energy concentration

3 3

of short-lived radon-222 decay products greater than 10 nJ/m and lower than 1 000 nJ/m .

NOTE For informative purposes only, this document also addresses the case of radon-220 decay products,

given the similarity in behaviour of the radon isotopes 222 and 220.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 11665-1, Measurement of radioactivity in the environment — Air: radon-222 — Part 1: Origins of radon

and its short-lived decay products and associated measurement methods

ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories

IEC 61577-1, Radiation protection instrumentation — Radon and radon decay product measuring

instruments — Part 1: General principles

IEC 61577-3, Radiation protection instrumentation — Radon and radon decay product measuring

instruments — Part 3: Specific requirements for radon decay product measuring instruments

3 Terms, definitions and symbols
3.1 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 11665-1 apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at http: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
© ISO 2019 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 11665-2:2020
ISO 11665-2:2019(E)
3.2 Symbols

For the purposes of this document, the symbols given in ISO 11665-1 and the following apply.

222

a attenuation coefficient relating to the Rn found in the collimators corresponding to the

range P (established theoretically and provided by the manufacturer)
222

b attenuation coefficient relating to the Rn found in the collimators corresponding to the

range P (established theoretically and provided by the manufacturer)
alpha particle energy produced by the disintegration of the nuclide i, in joules
AE,i

average potential alpha energy concentration of the nuclide i, in joules per cubic metre

PAEC,i

decision threshold of the average potential alpha energy concentration of the nuclide i, in

PAEC,i joules per cubic metre

detection limit of the average potential alpha energy concentration of the nuclide i, in

PAEC,i
joules per cubic metre

lower limit of the confidence interval of the average potential alpha energy concentration

PAEC,i
of the nuclide i, in joules per cubic metre

upper limit of the confidence interval of the average potential alpha energy concentration

PAEC,i of the nuclide i, in joules per cubic metre
n counting number of each range P
P range recording alpha particles for i = 1, 2, 3, 4
j number of net count of range P with deduced background for i = 1, 2, 3, 4
Pj,
mean number of net count of range P with deduced background for i = 1, 2, 3, 4
mean number of count due to background
212

r ratio between the number of alpha particles emitted by Bi (α emitter at 36 %) and

212

the number of alpha particles emitted by Po (produced by β disintegration at 64 %

212
of Bi); 0,56
U expanded uncertainty calculated by U = k⋅u( ) with k = 2
u( ) standard uncertainty associated with the measurement result
u ( ) relative standard uncertainty
rel
V sampled volume, in cubic metres

ε geometric detection efficiency (established theoretically), i.e. the ratio between the num-

ber of tracks counted and the number of alpha particles emitted by the deposit collected

on the filter

ε collection efficiency (established experimentally), i.e. the ratio between the number of

atoms of short-lived decay products collected per unit of sampled volume of air and the

number of atoms per unit of volume of air present in the detection system environment

2 © ISO 2019 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 11665-2:2020
ISO 11665-2:2019(E)
4 Principle

Integrated measurement of potential alpha energy concentration of short-lived radon decay products is

based on the following elements:

a) continuous sampling of short-lived radon decay products contained in an air volume representative

of the atmosphere under investigation, using a high-efficiency filtering membrane;

b) counting, and discriminating over four energy ranges, the alpha particles emitted by the collected

short-lived radon-222 decay products (alpha particles with an energy E and E
AE,218 AE,214
Po Po
218 214 214 214

produced by the disintegration of Po and Po, and the disintegration of Pb and Bi potential

emitters of alpha particles of this type), using a solid-state nuclear track detector;

c) calculation of the potential alpha energy concentration of the short-lived radon-222 decay products.

NOTE For the radon-220 decay products, this involves distinguishing between, and counting, the alpha

216 212

particles, with an energy E and E , released through disintegration of Po and Po, and

AE,212 AE,212
Bi Po
212 212
disintegration of Pb and Bi potential emitters of alpha particles of this type.
5 Equipment
5.1 General

The apparatus shall include a measuring device, composed of a sampling system and a detection system

(see Figure 1), and a counting system. The measuring device shall be in accordance with IEC 61577-1

and IEC 61577-3.
5.2 Measuring device
5.2.1 Sampling system
The sampling system shall include the following components:

a) a high-efficiency filtering membrane in cellulose acetate to collect the radon decay products;

b) a sampling pump which provides a volume rate compatible with the air and metrological

characteristics of the detection system;

c) a mass flow-meter which measures the flow-rate of air sampled throughout the sampling duration.

The sampling system is located downstream of the detection system.
5.2.2 Detection system
The detection system shall include the following components:

a) three boPET screens of different thickness placed at one end of the collimators are used to

discriminate between the particles over three energy ranges. This geometry is used to mitigate

the initial energy of each alpha particle emitted by the collected radionuclides in an energy range

compatible with the characteristics of the sensor (SSNTD) used;
b) a solid-state nuclear track detector (SSNTD).
© ISO 2019 – All rights reserved 3
---------------------- Page: 15 ----------------------
SIST EN ISO 11665-2:2020
ISO 11665-2:2019(E)
Key
1 solid state nuclear track detector (SSNTD)
2 air inlet
3 mass flow-meter
4 air outlet
5 vacuum pump
6 high-efficiency filter
7 baffles (diffusion barrier)
8 collimator
9 boPET (biaxially oriented polyethylene teraphthalate) screen
10 scanning range
Front view.
Side view.

Figure 1 — Example set-up of a measuring device for determination over four energy ranges of

average potential alpha energy concentration of short-lived radon-222 decay products

5.3 Counting system
The counting system shall include the following components:
a) equipment and suitable chemical reagents for etching the detector (SSNTD);

b) an optical microscope and associated equipment for scanning and counting the etched tracks.

6 Sampling
6.1 Sampling objective
The sampling objectiv
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.