EN ISO 20785-3:2023

SLOVENSKI STANDARD
01-september-2023
Dozimetrija za merjenje izpostavljenosti kozmičnemu sevanju v civilnem letalskem
prometu - 3. del: Meritve na višini letenja (ISO 20785-3:2023)
Dosimetry for exposures to cosmic radiation in civilian aircraft - Part 3: Measurements at
aviation altitudes (ISO 20785-3:2023)
Dosimetrie zu Expositionen durch kosmische Strahlung in Zivilluftfahrzeugen - Teil 3:
Messungen auf Flughöhen (ISO 20785-3:2023)
Dosimétrie pour les expositions au rayonnement cosmique à bord d'un avion civil - Partie
3: Mesurages à bord d'avions (ISO 20785-3:2023)
Ta slovenski standard je istoveten z: EN ISO 20785-3:2023
ICS:
17.240 Merjenje sevanja Radiation measurements
49.020 Letala in vesoljska vozila na Aircraft and space vehicles in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 20785-3
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2023
EUROPÄISCHE NORM
ICS 13.280; 17.240; 49.020 Supersedes EN ISO 20785-3:2017
English Version
Dosimetry for exposures to cosmic radiation in civilian
aircraft - Part 3: Measurements at aviation altitudes (ISO
20785-3:2023)
Dosimétrie pour les expositions au rayonnement Dosimetrie zu Expositionen durch kosmische
cosmique à bord d'un avion civil - Partie 3: Mesurages Strahlung in Zivilluftfahrzeugen - Teil 3: Messungen auf
à bord d'avions (ISO 20785-3:2023) Flughöhen (ISO 20785-3:2023)
This European Standard was approved by CEN on 10 June 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 20785-3:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 20785-3:2023) 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 December 2023, and conflicting national standards
shall be withdrawn at the latest by December 2023.
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 20785-3:2017.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. 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 20785-3:2023 has been approved by CEN as EN ISO 20785-3:2023 without any
modification.
INTERNATIONAL ISO
STANDARD 20785-3
Second edition
2023-06
Dosimetry for exposures to cosmic
radiation in civilian aircraft —
Part 3:
Measurements at aviation altitudes
Dosimétrie pour les expositions au rayonnement cosmique à bord
d'un avion civil —
Partie 3: Mesurages à bord d'avions
Reference number
ISO 20785-3:2023(E)
ISO 20785-3:2023(E)
© ISO 2023
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
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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 20785-3:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Quantities and units . 1
3.2 Atmospheric radiation field . 4
4 General considerations .5
4.1 General description of the cosmic radiation field in the atmosphere . 5
4.2 General considerations concerning the measurements . 7
4.2.1 General . 7
4.2.2 Selection of appropriate instruments . 7
4.2.3 Characterization of the responses of the instruments . 7
4.2.4 Measurements inside an aircraft . 7
4.2.5 Application of appropriate correction factors . 8
4.3 Safety and regulatory requirements for in-flight measurements . 8
5 Measurement at aviation altitude .8
5.1 Parameters determining the dose rate . 8
5.1.1 Barometric altitude . 8
5.1.2 Geographic coordinates . 8
5.1.3 Solar activity . 9
5.2 Possible influence quantities . 9
5.2.1 General . 9
5.2.2 Cabin air pressure . 9
5.2.3 Cabin air temperature . 9
5.2.4 Cabin air humidity . 9
5.3 Specific considerations for active instruments . 9
5.3.1 Power supply . . 9
5.3.2 Vibrations and shocks . 10
5.3.3 Electromagnetic interferences from the aircraft . 10
5.4 Specific considerations for passive measurements . 10
5.4.1 Security X-ray scanning . 10
5.4.2 Background subtraction . 10
6 Uncertainties .10
Annex A (informative) Representative particle fluence energy distributions for the cosmic
radiation field at flight altitudes for solar minimum and maximum conditions and
for minimum and maximum vertical cut-off rigidity .11
Bibliography .17
iii
ISO 20785-3:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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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 conv
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