EN 61577-3:2014

Radiation protection instrumentation - Radon and radon decay product measuring instruments - Part 3: Specific requirements for radon decay product measuring instruments

IEC 61577-3:2011 describes the specific requirements for instruments measuring the volumetric activity of airborne short-lived radon decay products and/or their ambient potential alpha-energy concentration outdoors, in dwellings, and in workplaces including underground mines. This standard applies practically to all types of electronic instruments that are based on grab sampling, continuous sampling technique and electronic integrating measurement methods. This new edition includes the following significant technical changes with respect to the previous edition: - implementation of new requirements and tests concerning radiation detection performance; - implementation of new requirements and tests concerning environmental performance; - harmonization of the requirements and tests concerning electrical and mechanical performance with other standards in the area of radiation protection instrumentation.

Strahlenschutz-Messgeräte - Geräte für die Messung von Radon und Radon-Folgeprodukten - Teil 3: Besondere Anforderungen an Messgeräte für Radonfolgeprodukte

Instrumentation pour la radioprotection - Instruments de mesure du radon et des descendants du radon - Partie 3: Exigences spécifiques concernant les instruments de mesure des descendants du radon

La CEI 61577-3:2011 décrit les exigences spécifiques relatives aux instruments destinés au mesurage de l'activité volumétrique des descendants du radon à vie courte en suspension dans l'air et/ou de leur énergie alpha potentielle volumique à l'extérieur, dans les habitations et sur les lieux de travail, y compris dans les mines souterraines. En pratique, la présente Norme s'applique à tous les types d'instruments électroniques utilisant des méthodes basées sur un prélèvement instantané, un prélèvement en continu et des méthodes de mesure électroniques intégrées. Cette nouvelle édition constitue une révision technique et inclut les changements techniques significatifs suivants par rapport à l'édition précédente: - ajout de nouvelles exigences et de nouveaux essais concernant les performances de détection de rayonnement; - ajout de nouvelles exigences et de nouveaux essais concernant les performances environnementales; - harmonisation des exigences et des essais, concernant les performances électriques et mécaniques, avec d'autres normes du domaine de l'instrumentation pour la radioprotection.

Instrumenti za zaščito pred sevanjem - Instrumenti za merjenje radona in njegovih razpadnih produktov - 3. del: Posebne zahteve za instrumente za merjenje razpadnih produktov radona

Standard IEC 61577-3:2011 opisuje posebne zahteve za instrumente, ki merijo volumetrično dejavnost kratkotrajnih razpadnih produktov radona v zraku in/ali njihove okoljske potencialne koncentracije alfa energije na prostem, v stanovanjih ter na delovnih mestih, vključno s podzemnimi rudniki. Ta standard se uporablja za skoraj vse vrste elektronskih instrumentov, ki temeljijo na zajemnem vzorčenju, tehniki neprekinjenega vzorčenja in metodah elektronskega integrirnega merjenja. Ta nova izdaja vključuje naslednje znatne tehnične spremembe glede na prejšnjo izdajo:
– izvajanje novih zahtev in preskusov v zvezi z učinkovitostjo zaznavanja sevanja;
– izvajanje novih zahtev in preskusov v zvezi z okoljsko učinkovitostjo;
– usklajevanje zahtev in preskusov v zvezi z električno in mehansko učinkovitostjo z drugimi standardi na področju instrumentov za zaščito proti sevanju.

General Information

• Status: Published
• Publication Date: 04-Dec-2014
• Withdrawal Date: 16-Nov-2017
• ICS: 13.280 - Radiation protection
• Technical Committee: CLC/TC 45B - Radiation protection instrumentation
• Drafting Committee: IEC/SC 45B - IEC_SC_45B
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 05-Dec-2014
• Completion Date: 05-Dec-2014
• Ref Project: SIST EN 61577-3:2015 - Radiation protection instrumentation - Radon and radon decay product measuring instruments - Part 3: Specific requirements for radon decay product measuring instruments

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2015
,QVWUXPHQWL]D]DãþLWRSUHGVHYDQMHP,QVWUXPHQWL]DPHUMHQMHUDGRQDLQQMHJRYLK
UD]SDGQLKSURGXNWRYGHO3RVHEQH]DKWHYH]DLQVWUXPHQWH]DPHUMHQMH
UD]SDGQLKSURGXNWRYUDGRQD
Radiation protection instrumentation - Radon and radon decay product measuring
instruments - Part 3: Specific requirements for radon decay product measuring
instruments
Strahlenschutz-Messgeräte - Geräte für die Messung von Radon und Radon-
Folgeprodukten - Teil 3: Besondere Anforderungen an Messgeräte für
Radonfolgeprodukte
Instrumentation pour la radioprotection - Instruments de mesure du radon et des
descendants du radon - Partie 3: Exigences spécifiques concernant les instruments de
mesure des descendants du radon
Ta slovenski standard je istoveten z: EN 61577-3:2014
ICS:
13.280 Varstvo pred sevanjem Radiation protection
17.240 Merjenje sevanja Radiation measurements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 61577-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2014
ICS 13.280
English Version
Radiation protection instrumentation - Radon and radon decay
product measuring instruments - Part 3: Specific requirements
for radon decay product measuring instruments
(IEC 61577-3:2011 , modified)
Instrumentation pour la radioprotection - Instruments de Strahlenschutz-Messgeräte - Geräte für die Messung von
mesure du radon et des descendants du radon - Partie 3: Radon und Radon-Folgeprodukten - Teil 3: Besondere
Exigences spécifiques concernant les instruments de Anforderungen an Messgeräte für Radonfolgeprodukte
mesure des descendants du radon (IEC 61577-3:2011 , modifiziert)
(CEI 61577-3:2011 , modifiée)
This European Standard was approved by CENELEC on 2014-11-17. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61577-3:2014 E
Foreword
This document (EN 61577-3:2014) consists of the text of IEC 61577-3:2011 prepared by IEC/SC 45B
"Radiation protection instrumentation" of IEC/TC 45 "Nuclear instrumentation", together with the
common modifications prepared by CLC/TC 45B "Radiation protection instrumentation".
The following dates are fixed:
(dop) 2015-11-17
• latest date by which this document has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dow) 2017-11-17
• latest date by which the national standards conflicting
with this document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
- 3 - EN 61577-3:2014
Endorsement notice
The text of the International Standard IEC 61577-3:2011 was approved by CENELEC as a European
Standard with agreed common modifications.

COMMON MODIFICATIONS
2 Normative references
Add IEC 61577-1 and IEC 61577-4.

6 Test conditions
6.4 Test sources
6.4.2 Reference atmospheres
Replace in the second paragraph 150 nm with 100 nm.

9 Requirements and tests concerning environmental performance
9.2 Number concentration of aerosols
9.2.2 Test method
8 –3
Replace in the second paragraph “adjusted to 10 m with an accuracy of ± 10 %.” with
8 –3
“adjusted to about 10 m .”
10 –3 10 –3 12 –3
Replace in the third paragraph “10 m ” with “about 10 m ” and replace “10 m ” with
12 –3
“about 10 m ”
Table 1 – Reference conditions and standard test conditions
Replace the line for ambient temperature as follows:
Ambient temperature 20 °C 18 °C to 24 °C
Replace the line for relative humidity as follows:
Relative humidity 65 % 40 % to 75 %
Replace the line for ambient dose equivalent rate as follows:
Ambient dose
–1
Negligible < 0,25 µSv⋅h
equivalent rate
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is
available here: www.cenelec.eu.

Publication Year Title EN/HD Year
IEC 60050-394 -  International Electrotechnical - -
Vocabulary (IEV) -
Part 394: Nuclear instrumentation -
Instruments, systems, equipment and
detectors
IEC 60068-2-27 -  Environmental testing - EN 60068-2-27 -
Part 2-27: Tests - Test Ea and
guidance: Shock
IEC 61000-6-4 -  Electromagnetic compatibility (EMC) - -
EN 61000-6-4
Part 6-4: Generic standards - Emission
standard for industrial environments
IEC 61140 -  Protection against electric shock - -
EN 61140
Common aspects for installation and
equipment
IEC 61187 -  Electrical and electronic measuring EN 61187 -
equipment - Documentation
IEC 61577-1 - Radiation protection instrumentation - - -
Radon and radon decay product
measuring instruments -
Part 1: General principles
IEC 61577-4 - Radiation protection instrumentation - EN 61577-4 -
Radon and radon decay product
measuring instruments -
Part 4: Equipment for the production of
reference atmospheres containing
radon isotopes and their decay products
(STAR)
ISO/IEC Guide 98-3 2008 Uncertainty of measurement - - -
Part 3: Guide to the expression of
uncertainty in measurement
(GUM:1995)
IEC 61577-3 ®
Edition 2.0 2011-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Radiation protection instrumentation – Radon and radon decay product
measuring instruments –
Part 3: Specific requirements for radon decay product measuring instruments

Instrumentation pour la radioprotection – Instruments de mesure du radon et
des descendants du radon –
Partie 3: Exigences spécifiques concernant les instruments de mesure des
descendants du radon
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX U
ICS 13.280 ISBN 978-2-88912-839-6

– 2 – 61577-3 © IEC:2011
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 General design considerations . 10
4.1 Design considerations for the measurements . 10
4.1.1 Deposition of radon decay products on surfaces . 10
4.1.2 Airflow system . 11
4.2 Design considerations for handling and maintenance . 11
4.2.1 Portability . 11
4.2.2 Application under heavy environmental conditions . 11
4.2.3 Automatic operation . 11
4.2.4 Reliability . 11
4.2.5 Capability for operational testing . 12
4.2.6 Adjustment and maintenance facilities . 12
4.2.7 Acoustic noise level . 12
4.2.8 Electromagnetic interference . 12
4.2.9 Storage . 12
5 Technical components . 12
5.1 Sampling assembly . 12
5.2 Radiation detection assembly . 13
5.3 Data processing and recording . 13
5.4 Measurement display . 13
5.5 Power supply . 14
6 Test conditions . 14
6.1 General . 14
6.2 Standard test conditions . 15
6.3 Execution of tests . 15
6.4 Test sources . 15
6.4.1 Solid sources . 15
6.4.2 Reference atmospheres . 15
7 Requirements and tests concerning radiation detection performance . 16
7.1 Reference response to a test source . 16
7.1.1 Requirements . 16
7.1.2 Test method . 16
7.2 Cross interference to other radon isotopes . 16
7.2.1 Requirements . 16
7.2.2 Test method . 16
7.3 Linearity of indication . 17
7.3.1 Requirements . 17
7.3.2 Test method . 17
7.4 Instrument statistical fluctuation . 17
7.4.1 Requirements . 17
7.4.2 Test method . 17
7.5 Response time . 18

61577-3 © IEC:2011 – 3 –
7.5.1 Requirements . 18
7.5.2 Test method . 18
7.6 Signal accumulation . 18
7.6.1 Requirements . 18
7.6.2 Test method . 19
8 Requirements and tests concerning air circuit performance . 19
8.1 General . 19
8.2 Flow-rate stability . 19
8.2.1 Requirements . 19
8.2.2 Test method . 19
8.3 Accuracy of the flow-rate measurement . 19
8.3.1 Requirements . 19
8.3.2 Test method . 19
8.4 Effect of filter pressure drop . 20
8.4.1 Requirements . 20
8.4.2 Test method . 20
8.5 Low sampling flow-rate indication . 20
8.5.1 Requirements . 20
8.5.2 Test method . 20
9 Requirements and tests concerning environmental performance . 20
9.1 Response to ambient gamma radiation . 20
9.1.1 Requirements . 20
9.1.2 Test method . 21
9.2 Number concentration of aerosols . 21
9.2.1 Requirements . 21
9.2.2 Test method . 21
9.3 Ambient temperature . 21
9.3.1 Requirements . 21
9.3.2 Test method . 21
9.4 Relative humidity and condensed moisture . 21
9.4.1 Requirements . 21
9.4.2 Test method . 22
9.5 Atmospheric pressure . 22
10 Requirements and tests concerning electrical performance . 22
10.1 Warm-up time . 22
10.1.1 Requirements . 22
10.1.2 Test method . 22
10.2 Power supply variations. 22
10.2.1 Requirements . 22
10.2.2 Test method . 23
10.3 Battery test . 23
10.3.1 Requirements . 23
10.3.2 Test method . 23
11 Requirements and tests concerning mechanical performance . 23
11.1 Requirements . 23
11.2 Test method . 23
12 Operation and maintenance manual . 24
13 Type test report and certificate . 24

– 4 – 61577-3 © IEC:2011
Table 1 – Reference conditions and standard test conditions (unless otherwise
indicated by the manufacturer) . 25
Table 2 – Tests of the radiation detection performance . 26
Table 3 – Tests performed with variation of influence quantities. 26
Table 4 – Tests of the air circuit . 26

61577-3 © IEC:2011 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RADIATION PROTECTION INSTRUMENTATION –
RADON AND RADON DECAY PRODUCT
MEASURING INSTRUMENTS –
Part 3: Specific requirements for radon decay product
measuring instruments
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61577-3 has been prepared by sub-committee 45B: Radiation
protection instrumentation, of IEC technical committee 45: Nuclear instrumentation.
This second edition of IEC 61577-3 cancels and replaces IEC 61577-3:2002 and
IEC 61263:1994. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– Implementation of new requirements and tests concerning radiation detection
performance.
– Implementation of new requirements and tests concerning environmental performance.

– 6 – 61577-3 © IEC:2011
– Harmonization of the requirements and tests concerning electrical and mechanical
performance with other standards in the area of radiation protection instrumentation.
The text of this standard is based on the following documents:
FDIS Report on voting
45B/700/FDIS 45B/716/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 61577 series, under the general title Radiation protection
instrumentation – Radon and radon decay product measuring instruments, can be found on
the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
61577-3 © IEC:2011 – 7 –
INTRODUCTION
226 223 224
Radon is a radioactive trace gas produced by the decay of Ra, Ra and Ra,
238 235 232
respectively decay products of U, U and Th which are present in the earth's crust. By
222 219 220
decay, radon isotopes (i.e., Rn, Rn, Rn) produce three decay chains, each ending in a
stable lead isotope. The radon isotope Rn generally is called thoron .
NOTE In normal conditions, due to the very short half-life of Rn, its activity and the activity of its RnDP are
considered negligible compared to the activity of the two other series. Its health effects are therefore not important.
Thus in this standard Rn and its decay products are not considered.
Radon isotopes and their corresponding short-lived Radon Decay Products (RnDP) (i.e.,
218 214 214 214 222 216 212 212 212 208 220
Po, Pb, Bi, Po for Rn, and Po, Pb, Bi, Po, Tl for Rn) are of
considerable importance, as they constitute the major part of the radiological exposure to
natural radioactivity for the general public and workers. In some workplaces such as
underground mines, spas and waterworks, the workers are exposed to very significant levels
of RnDP. Various quantities of these radionuclides are airborne in a gaseous form for the
radon isotopes and as particulates for the radon decay products. It is worthwhile for health
physicists to be able to measure with a great accuracy the level of this kind of natural
radioactivity in the atmosphere. Because of the unique behaviour of these radioactive
elements in the atmosphere and in the corresponding measuring instruments, it is necessary
to formalize the way such instruments could be tested.
The standard series IEC 61577 covers specific requirements concerning test and calibration
of radon and radon decay product measuring instruments. In order to facilitate its use, the
IEC 61577 series is divided into the following different parts:
IEC 61577-1 (Normative): This part deals with the terminology and units used in the specific
area of radon and radon decay products (RnDP) measurements and describes briefly the
System for Test Atmospheres with Radon (STAR) used for test and calibration of radon and
RnDP measuring devices.
222 220
IEC 61577-2 (Normative): This part is dedicated to the test of Rn and Rn measuring
instruments.
IEC 61577-3 (Normative): This part is dedicated to the test of RnDP and RnDP
222 220
measuring instruments.
IEC 61577-4 (Normative): This part describes the construction of a STAR and its use for
testing.
IEC 61577-5 (Informative): This is a technical guide concerning special features of radon and
radon decay products as well as their measurement.

___________
The term thoron is not used in this standard. Instead, the term radon is used to denote the radionuclides Rn
and Rn. In the case of only one radionuclide being explicitely specified, the atomic mass number and the
chemical symbol will be given.
RnDP is the acronym of Radon Decay Products which are sometimes denoted as radon progeny. The term
Radon Decay Product or its abbreviation (RnDP) denotes the whole set of short-lived decay products that are
the focus of this standard. A particular isotope is indicated by its chemical symbol preceded by its mass
number. The subscripts , added to the symbol RnDP refer to the whole set of short-lived decay products
222 220
218 214 214 214 216 212 212
of the corresponding radon isotope (RnDP : Po, Pb, Bi, Po, and RnDP : Po, Pb, Bi,
222 220
212 208
Po, Tl).
– 8 – 61577-3 © IEC:2011
RADIATION PROTECTION INSTRUMENTATION –
RADON AND RADON DECAY PRODUCT
MEASURING INSTRUMENTS –
Part 3: Specific requirements for radon decay product
measuring instruments
1 Scope
This part of IEC 61577 describes the specific requirements for instruments measuring the
volumetric activity of airborne short-lived radon decay products and/or their ambient potential
alpha-energy concentration outdoors, in dwellings, and in workplaces including underground
mines.
This standard applies practically to all types of electronic instruments that are based on grab
sampling, continuous sampling technique and electronic integrating measurement methods.
The measurement of activity retained by a sampling device, for example a filtering device, can
be performed both during sampling or after the completion of a collection cycle.
The different types of instrumentation used for measurements are stated in IEC 61577-1.
2 Normative references
The following references are indispensable in applying this document. For dated references,
only the cited edition applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
IEC 60050-394, International Electrotechnical Vocabulary (IEV) – Part 394: Nuclear
instrumentation – Instruments, systems, equipment and detectors
IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 61000-6-4, Electromagnetic compatibility (EMC) – Part 6-4: Generic standards –
Emission standard for industrial environments
IEC 61140, Protection against electric shock – Common aspects for installation and
equipment
IEC 61187, Electrical and electronic measuring equipment – Documentation
ISO/IEC Guide 98-3:2008, Uncertainty of measurement – Part 3: Guide to the expression of
uncertainty in measurement (GUM:1995)
3 Terms and definitions
For the purposes of this document, the terms and definitions of IEC 60050-394 apply as well
as the following:
3.1
conventionally true value of a quantity
value attributed to a particular quantity and accepted, sometimes by convention, as having an
uncertainty appropriate for a given purpose

61577-3 © IEC:2011 – 9 –
NOTE "Conventionally true value of a quantity" is sometimes called assigned value, best estimate of the value,
conventional value or reference value.
[IEC 60050-394:2007, 394-40-10]
3.2
rated range
range of a quantity to be measured, observed, supplied, or set, assigned to the instrument
[IEC 60050-394:2007, 394-39-42]
3.3
error (of measurement)
result of a measurement minus a true value of the measurand
NOTE 1 Since a true value cannot be determined, in practice a conventionally true value is used.
NOTE 2 When it is necessary to distinguish "error" from "relative error", the former is sometimes called “absolute
error of measurement”. This should not be confused with “absolute value of error”, which is the modulus of the
error.
[IEC 60050-394:2007, 394-40-13]
3.4
relative error
error of measurement divided by a true value of the measurand
NOTE Since a true value cannot be determined, in practice a conventionally true value is used.
[IEC 60050-394:2007, 394-40-11]
3.5
intrinsic error
error of a measuring instrument, determined under reference conditions
[IEC 60050-394:2007, 394-40-12]
3.6
response (of a radiation measuring assembly)
ratio, under specified conditions, given by the relation :
ν
R =
ν
c
where ν is the value measured by the equipment or assembly under test and ν is the
c
conventionally true value of this quantity.
NOTE 1 The input signal to a measuring system may be called the stimulus; the output signal may be called the
response (IVM).
NOTE 2 Response can have several definitions. As an example, the definition of the response of a radiation
measuring assembly is given.
[IEC 60050-394:2007, 394-40-21]
3.7
reference response
response of the assembly under reference conditions to a reference dose rate or activity
expressed as:
– 10 – 61577-3 © IEC:2011
ν
R =
ref
ν
c
where ν is the value measured by the equipment or assembly under test and ν is the
c
conventionally true value of the reference source
NOTE The background value may be automatically taken in account by an algorithm included in the measurement
system.
[IEC 60050-394:2007, 394-40-22]
3.8
cross-interference
ratio of the response of the instrument to the radiation from an interfering radionuclide to the
response of the radiation from the radionuclide of interest
NOTE In the context of this standard the term cross-interference is used to characterize the falsification of
RnDP on the indication of instruments measuring quantities of RnDP , and vice versa.
220 222
3.9
coefficient of variation
ratio of the standard deviation s to the arithmetic mean x of a set of n measurements x given
i
by the following formula:
(x − x )
s 1 ∑ i
V = =
x x n − 1
[IEC 60050-394:2007, 394-40-14]
3.10
response time (of a measuring assembly)
duration between the instant of a step change in the measured quantity and the instant when
the output signal reaches for the first time a specified percentage of its final value, with that
percentage being usually taken as 90 %
[IEC 60050-394:2007, 394-39-09]
4 General design considerations
4.1 Design considerations for the measurements
4.1.1 Deposition of radon decay products on surfaces
After the decay of radon, the freshly generated radon decay products form clusters
(particulate diameters in the order of magnitude of nm) some of which are attached to the
ambient aerosol, and the fraction of attached clusters are referred to as attached fraction of
radon decay products. The part of free clusters denotes the unattached fraction. The
unattached fraction of decay products has a high mobility and deposits preferably on
surfaces.
The deposition of radon decay products on surfaces results in a depletion in the vicinity of the
instrument and can cause distortion of the measurements. In order to minimize these effects
an open face air sampling is preferred.
In cases where open face air sampling is not applicable, the manufacturer shall specify the
relative error in relation to the unattached fraction of the radon decay products.
NOTE Freshly formed radon decay products appear to be mainly positive in the atmosphere, their size increases
rapidly by clustering with surrounding molecules in the air (water, trace gases). These ultrafine particles with

61577-3 © IEC:2011 – 11 –
thermodynamic diameters in the conventional range of less than 5 nm are called the unattached fraction. Wire
screens are commonly used for the measurement of the unattached fraction.
4.1.2 Airflow system
Instruments operating with air sampling shall be appropriately designed and constructed to
avert recirculation between the air inlet and the air exhaust. The minimum distance between
air inlet and outlet shall be agreed upon between manufacturer and purchaser.
The design of the air sampling system should avoid turbulences. The impact of flow-rate and
pressure drop on the measurement shall be agreed upon between manufacturer and
purchaser.
4.2 Design considerations for handling and maintenance
4.2.1 Portability
The instrument shall be designed to be easily carried by hand in order to perform in-situ
measurements. This requires, in particular, robustness against mechanical shock.
4.2.2 Application under heavy environmental conditions
If the instrument is applied under heavy environmental conditions occurring mostly outdoors
or at workplaces, in particular in mines, the instrument shall be of rugged construction. Where
applicable appropriate measures shall be met to protect the instrument and its components
against external influences or conditions such as
a) mechanical impacts;
b) corrosion and corrosive solvents;
c) fungus;
d) vermin;
e) solar radiation;
f) ice formation;
g) moisture and spraying water;
h) explosive atmospheres.
In cases where the impact of external influences cannot be eliminated totally, the influences
shall not affect the satisfactory operation of the instrument or compromise safety. Spray water
shall have no harmful effects.
The manufacturer shall specify the minimum ranges of environmental conditions or external
influences within which satisfactory operation of the instrument is ensured. The manufacturer
shall state influences or conditions that significantly reduce the measurement capability of the
instrument.
The manufacturer shall explicitly state whether the instrument can be used in explosive
atmospheres (e.g., in mines) or not.
4.2.3 Automatic operation
The instrument shall be such that the measurement cycle can be carried out either manually
or with programming so that automatic operation can be achievable.
4.2.4 Reliability
The instrument shall be designed to provide reliable performance with failures kept to a
minimum.
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4.2.5 Capability for operational testing
Capability should be provided to allow the purchaser to carry out periodic checks of the
operation of the instrument.
These checks shall be carried out using one or more suitable radioactive sources as
necessary.
4.2.6 Adjustment and maintenance facilities
All electronic components shall be provided with a sufficient numbers of accessible and
identifiable test points to facilitate adjustments and fault location. Any special maintenance
tools and appropriate maintenance manuals shall be supplied.
The design of all components shall be such as to facilitate ease of repair and maintenance.
4.2.7 Acoustic noise level
Acoustic noise level of the instrument shall arise mainly from the sampling assembly and its
resultant vibration.
The manufacturer should select the components and design the instrument so that the noise
level is minimized. In particular, for instruments that are used indoors, the reduction of
acoustic noise level shall be taken into consideration.
4.2.8 Electromagnetic interference
All necessary precautions shall be taken against detrimental effects of electromagnetic
interference on or by the instrument.
The manufacturer shall quantify the electromagnetic emission of the equipment. The emission
limits applicable to the instrument covered by this standard are given in IEC 61000-6-4.
Moreover, the manufacturer shall state the influence of cellular phones and walkie-talkies on
the instrument at a given distance and give appropriate warning.
4.2.9 Storage
The instrument shall remain operable within the specified requirements of this standard after
storage without batteries and transportation in the manufacturer’s packaging at any
temperature between –25 °C and +60 °C. In some cases, more severe requirements may be
stated such as capability to withstand air transportation at low atmospheric pressure.
5 Technical components
5.1 Sampling assembly
The sampling assembly can include the following components and functional units:
a) sampling and exhaust pipes;
b) air sampling inlet;
c) aerosol retention device;
d) air pump;
e) flow-rate control and measurement system.
An open face sampling inlet is recommended. The sampling device shall be designed to
minimize particle losses.
61577-3 © IEC:2011 – 13 –
In the case where an air filter is applied for aerosol retention and sampling of airborne
radionuclides, a high-efficiency particle filter (HEPA) should be applied. The manufacturer
shall state the type of the filter.
Access to the filter shall be designed so as to permit fast and easy removal. Attention shall be
given to the air seal around the filter so as to minimize leakage between the filter and the filter
holder. Warning shall be given that the pressure drop is such that a filter change is
necessary. The design shall enable the filter to be changed easily without damage.
The air pump shall be placed downstream from a filter or any other sampling unit, and shall be
able to withstand the variations of pressure induced by operation conditions, filter types, and
atmospheric dust-mass blockage. The pump shall be capable of continuous operation
between scheduled maintenance operations.
The range of acceptable flow-rates shall be stated by the manufacturer. If the measurements
are influenced by flow-rate, a flow-rate control device shall be provided that has a flow-rate
adjustment range sufficient to allow for variation in the intrinsic characteristics of the air pump
and any filters used. If the flow-rate is to be measured and indicated, the pressure and the
temperature at which the flow-rate meter is calibrated and at which the flow-rate is expressed
shall be provided.
5.2 Radiation detection assembly
The radiation detection assembly produces an electrical signal related to the radiation emitted
by the sampled radon decay products incident on the detector. The efficiency of detection
shall be optimized.
Contamination of the detector may increase the background. Precautions shall be taken for
the protection against contamination, when the instrument is not in use. Wherever possible,
the radiation-detector window should be protected by a removable thin screen, or a rugged
solid-state detector should be used.
NOTE The contamination can be caused by:
– deposition of airborne decay products;
– recoil of sampled decay products.
5.3 Data processing and recording
This assembly comprises functional units for acquiring and processing signals supplied by the
detector.
The manufacturer shall publish the relevant measurement principles and procedures used to
produce the measurement result and its uncertainties. The detail of information shall facilitate
the verification of measurement results by the purchaser.
The electronic data recording system shall have the capacity sufficient for recording all
measurement data, including the spectrometry data generated during a long autonomous
data-acquisition period. The data shall be retained on a media that ensures the protection and
availability of the data, especially in the event of malfunction and interruption of operation or
failure of power supply. The manufacturer shall specify the capacity of the data recording
system.
5.4 Measurement display
The display shall be easily readable in different ambient conditions. The measurement units
shall be clearly marked on the display. If needed by the measurement method, the indication
of the flow-rate, the atmospheric air pressure and the ambient temperature shall be provided.
The display shall show one or more of the following quantities:

– 14 – 61577-3 © IEC:2011
– the activity concentration of radon decay products;
– the potential alpha energy concentration or exposure;
– the equilibrium equivalent radon concentration.
The quantities shall be given in combined SI-units. Appropriate submultiples should be used.
The display should show the unc
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