SIST EN ISO 4037-1:2021

Radiological protection - X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy - Part 1: Radiation characteristics and production methods (ISO 4037-1:2019)

This document specifies the characteristics and production methods of X and gamma reference radiation for calibrating protection-level dosemeters and doserate meters with respect to the phantom related operational quantities of the International Commission on Radiation Units and Measurements (ICRU)[5]. The lowest air kerma rate for which this standard is applicable is 1 µGy h?1. Below this air kerma rate the (natural) background radiation needs special consideration and this is not included in this document.
For the radiation qualities specified in Clauses 4 to 6, sufficient published information is available to specify the requirements for all relevant parameters of the matched or characterized reference fields in order to achieve the targeted overall uncertainty (k = 2) of about 6 % to 10 % for the phantom related operational quantities. The X ray radiation fields described in the informative Annexes A to C are not designated as reference X-radiation fields.
NOTE The first edition of ISO 4037-1, issued in 1996, included some additional radiation qualities for which such published information is not available. These are fluorescent radiations, the gamma radiation of the radionuclide 241Am, S-Am, and the high energy photon radiations R-Ti and R-Ni, which have been removed from the main part of this document. The most widely used radiations, the fluorescent radiations and the gamma radiation of the radionuclide 241Am, S-Am, are included nearly unchanged in the informative Annexes A and B. The informative Annex C gives additional X radiation fields, which are specified by the quality index.
The methods for producing a group of reference radiations for a particular photon-energy range are described in Clauses 4 to 6, which define the characteristics of these radiations. The three groups of reference radiation are:
a) in the energy range from about 8 keV to 330 keV, continuous filtered X radiation;
b) in the energy range 600 keV to 1,3 MeV, gamma radiation emitted by radionuclides;
c) in the energy range 4 MeV to 9 MeV, photon radiation produced by accelerators.
The reference radiation field most suitable for the intended application can be selected from Table 1, which gives an overview of all reference radiation qualities specified in Clauses 4 to 6. It does not include the radiations specified in the Annexes A, B and C.
The requirements and methods given in Clauses 4 to 6 are targeted at an overall uncertainty (k = 2) of the dose(rate) value of about 6 % to 10 % for the phantom related operational quantities in the reference fields. To achieve this, two production methods are proposed:
The first one is to produce "matched reference fields", whose properties are sufficiently well-characterized so as to allow the use of the conversion coefficients recommended in ISO 4037-3. The existence of only a small difference in the spectral distribution of the "matched reference field" compared to the nominal reference field is validated by procedures, which are given and described in detail in ISO 4037‑2. For matched reference radiation fields, recommended conversion coefficients are given in ISO 4037‑3 only for specified distances between source and dosemeter, e.g., 1,0 m and 2,5 m. For other distances, the user has to decide if these conversion coefficients can be used. If both values are very similar, e.g., differ only by 2 % or less, then a linear interpolation may be used.
The second method is to produce "characterized reference fields

Strahlenschutz - Röntgen- und Gamma-Referenzstrahlungsfelder zur Kalibrierung von Dosimetern und Dosisleistungsmessgeräten und zur Bestimmung ihres Ansprechvermögens als Funktion der Photonenenergie - Teil 1: Strahlungseigenschaften und Erzeugungsmethoden

Dieses Dokument legt die Methoden für Erzeugung und Charakterisierung von Röntgen- und Gamma-Refe-renzstrahlungsfeldern zur Kalibrierung von Dosimetern und Dosisleistungsmessgeräten für den Strahlen-schutz in Bezug auf die phantombezogenen Messgrößen der Internationalen Kommission für Einheiten und Messungen (ICRU) 5 fest. Die kleinste Luftkermaleistung, für die diese Norm anwendbar ist, ist 1 µGy h–1. Unterhalb dieser Luftkermaleistung erfordert die (natürliche) Untergrundstrahlung die Berücksichtigung besonderer Gesichtspunkte und dies ist in diesem Dokument nicht enthalten.
Für die Strahlungsqualitäten, die in den Abschnitten 4 bis 6 festgelegt sind, sind ausreichend veröffentlichte Informationen verfügbar, um die Anforderungen an alle relevanten Parameter der übereinstimmenden oder charakterisierten Referenzstrahlungsfelder derart festzulegen, dass für die phantombezogenen Messgrößen die angestrebte Gesamt-Messunsicherheit (k = 2) von etwa 6 % bis 10 % erreicht wird. Die Röntgenstrah-lungsfelder, die in den informativen Anhängen A bis C beschrieben sind, gelten nicht als Röntgen-Referenz-strahlungsqualitäten.
ANMERKUNG   Die erste, 1996 herausgegebene, Ausgabe von ISO 4037 1 beinhaltete einige weitere Strahlungs¬qualitäten, für die derartige veröffentlichte Informationen nicht verfügbar sind. Diese sind Fluoreszenzstrahlungen, die Gammastrahlung des Radionuklids 241Am, S-Am, und die hochenergetischen Photonenstrahlungen R-Ti und R-Ni, die aus dem Hauptteil dieses Dokumentes entfernt wurden. Die am häufigsten verwendeten Strahlungsqualitäten, die Fluor¬eszenzstrahlungen und die Gammastrahlung des Radionuklids 241Am, S-Am, sind nahezu unverändert in die informati¬ven Anhänge A und B eingefügt. Der informative Anhang C beschreibt zusätzliche Röntgen-Strahlungsfelder, die mittels des Qualitätsindexes festgelegt sind.
Die Verfahren, um eine Gruppe von Referenzstrahlungsfeldern für einen bestimmten Bereich der Photonen-energie zu erzeugen, sind in den drei Abschnitten 4 bis 6 angegeben, die die Merkmale dieser Strahlungen beschreiben. Die drei Gruppen von Referenzstrahlungsfeldern sind:
a)   Kontinuierliche gefilterte Röntgenstrahlung im Energiebereich von etwa 8 keV bis 330 keV;
b)   von Radionukliden emittiert Gammastrahlung im Energiebereich von 600 keV bis 1,3 MeV;
c)   mittels Beschleunigern erzeugt Photonenstrahlung im Energiebereich von 4 MeV bis 9 MeV.
Das Referenzstrahlungsfeld, das für die beabsichtigte Anwendung am besten geeignet ist, kann aus Tabel-le 1 ausgewählt werden. Diese Tabelle gibt einen Überblick über alle Referenzstrahlungsqualitäten, die in den Abschnitten 4 bis 6 festgelegt sind. Sie beinhaltet nicht die in den Anhängen A, B und C festgelegten Strahlungsqualitäten.
Die Anforderungen und Methoden, die in den Abschnitten 4 bis 6 angegeben sind, sind darauf ausgerichtet, für die Werte der Dosis oder Dosisleistung der phantombezogenen Messgrößen eine Gesamt-Messunsicher-heit (k = 2) von etwa 6 % bis 10 % zu erzielen. Um dies zu erreichen, werden zwei Erzeugungsmethoden vorgeschlagen.
[...]

Radioprotection - Rayonnements X et gamma de référence pour l'étalonnage des dosimètres et des débitmètres, et pour la détermination de leur réponse en fonction de l'énergie des photons - Partie 1: Caractéristiques des rayonnements et méthodes de production (ISO 4037-1:2019)

Le présent document spécifie les caractéristiques et les méthodes de production des rayonnements X et gamma de référence pour l'étalonnage des dosimètres et des débitmètres de radioprotection par rapport aux grandeurs opérationnelles associées aux fantômes de l'International Commission on Radiation Units et Measurements (ICRU)[5]. Le plus petit débit de kerma dans l'air pour lequel la présente norme est applicable est de 1 µGy⋅h?1. En dessous de ce débit de kerma dans l'air, le rayonnement de bruit de fond (naturel) nécessite une attention particulière et cet aspect n'est pas couvert par le présent document.
En ce qui concerne les qualités de rayonnement spécifiées dans les Articles 4 à 6, les informations publiées sont suffisantes pour spécifier les exigences applicables à tous les paramètres pertinents des champs de référence adaptés ou caractérisés afin d'obtenir l'incertitude globale (k = 2) ciblée comprise entre environ 6 % et 10 % pour les grandeurs opérationnelles associées au fantôme. Les champs de rayonnement X décrits dans les Annexes A à C informatives ne sont pas considérés comme des champs de rayonnement X de référence.
NOTE La première édition de l'ISO 4037‑1, parue en 1996, incluait quelques qualités de rayonnement supplémentaires pour lesquelles aucune information de ce type n'a été publiée. Il s'agit des rayonnements de fluorescence, du rayonnement gamma du radionucléide 241Am, S-Am, et des rayonnements de photons de haute énergie R-Ti et R-Ni, qui ont été retirés de la partie principale du présent document. Les rayonnements les plus couramment utilisés, les rayonnements fluorescents et le rayonnement gamma du radionucléide 241Am, S-Am, sont inclus dans les Annexes A et B informatives qui n'ont presque pas été modifiées. L'Annexe C informative donne des champs de rayonnement X supplémentaires, qui sont spécifiés par l'indice de qualité.
Les méthodes de production d'un groupe de rayonnements de référence pour une gamme d'énergie donnée sont définies dans les Articles 4 à 6, qui précisent les caractéristiques de ces rayonnements. Les trois groupes de rayonnement de référence sont:
a) dans la gamme des énergies comprises approximativement entre 8 keV et 330 keV, des rayonnements X filtrés à tension constante;
b) dans la gamme d'énergie de 600 keV à 1,3 MeV, les rayonnements gamma émis par des radionucléides;
c) dans la gamme d'énergie de 4 MeV à 9 MeV, les rayonnements de photons produits par des accélérateurs.
Le champ de rayonnement de référence le mieux adapté à l'application prévue peut être sélectionné à partir du Tableau 1, qui donne une vue d'ensemble de toutes les qualités de rayonnement de référence spécifiées dans les Articles 4 à 6. Il n'inclut pas les rayonnements spécifiés dans les Annexes A, B et C.
Les exigences et méthodes données dans les Articles 4 à 6 ciblent une incertitude globale (k = 2) de la valeur (de débit) de dose d'environ 6 % à 10 % pour les grandeurs opérationnelles associées aux fantômes dans les champs de référence. À cet effet, deux méthodes de production sont proposées.
La première consiste à produire des «champs de référence adaptés», dont les propriétés sont suffisamment bien caractérisées pour permettre l'utilisation des coefficients de conversion recommandés dans l'ISO 4037‑3. Les «champs de référence adaptés» ne présentent qu'une légère différence de distribution spectrale par rapport au champ de référence nominal, qui est validée par des procédures qui sont données et décrit

Radiološka zaščita - Referenčno sevanje z rentgenskimi in gama žarki za kalibracijo dozimetrov in merilnikov doze sevanja ter za ugotavljanje njihovega odzivanja kot funkcije fotonske energije - 1. del: Značilnosti sevanja in proizvodne metode (ISO 4037-1:2019)

General Information

• Status: Published
• Public Enquiry End Date: 16-Dec-2020
• Publication Date: 21-Feb-2021
• ICS: 13.280 - Radiation protection
• ICS: 17.240 - Radiation measurements
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Feb-2021
• Due Date: 25-Apr-2021
• Completion Date: 22-Feb-2021
• Ref Project: EN ISO 4037-1:2021 - Radiological protection - X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy - Part 1: Radiation characteristics and production methods (ISO 4037-1:2019)

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 4037-1:2021
01-april-2021
Radiološka zaščita - Referenčno sevanje z rentgenskimi in gama žarki za
kalibracijo dozimetrov in merilnikov doze sevanja ter za ugotavljanje njihovega
odzivanja kot funkcije fotonske energije - 1. del: Značilnosti sevanja in proizvodne
metode (ISO 4037-1:2019)
Radiological protection - X and gamma reference radiation for calibrating dosemeters
and doserate meters and for determining their response as a function of photon energy -
Part 1: Radiation characteristics and production methods (ISO 4037-1:2019)
Strahlenschutz - Röntgen- und Gamma-Referenzstrahlungsfelder zur Kalibrierung von
Dosimetern und Dosisleistungsmessgeräten und zur Bestimmung ihres
Ansprechvermögens als Funktion der Photonenenergie - Teil 1: Strahlungseigenschaften
und Erzeugungsmethoden
Radioprotection - Rayonnements X et gamma de référence pour l'étalonnage des
dosimètres et des débitmètres, et pour la détermination de leur réponse en fonction de
l'énergie des photons - Partie 1: Caractéristiques des rayonnements et méthodes de
production (ISO 4037-1:2019)
Ta slovenski standard je istoveten z: EN ISO 4037-1:2021
ICS:
13.280 Varstvo pred sevanjem Radiation protection
17.240 Merjenje sevanja Radiation measurements
SIST EN ISO 4037-1:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 4037-1:2021

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SIST EN ISO 4037-1:2021


EN ISO 4037-1
EUROPEAN STANDARD

NORME EUROPÉENNE

February 2021
EUROPÄISCHE NORM
ICS 17.240
English Version

Radiological protection - X and gamma reference radiation
for calibrating dosemeters and doserate meters and for
determining their response as a function of photon energy
- Part 1: Radiation characteristics and production methods
(ISO 4037-1:2019)
Radioprotection - Rayonnements X et gamma de Strahlenschutz - Röntgen- und Gamma-
référence pour l'étalonnage des dosimètres et des Referenzstrahlungsfelder zur Kalibrierung von
débitmètres, et pour la détermination de leur réponse Dosimetern und Dosisleistungsmessgeräten und zur
en fonction de l'énergie des photons - Partie 1: Bestimmung ihres Ansprechvermögens als Funktion
Caractéristiques des rayonnements et méthodes de der Photonenenergie - Teil 1: Strahlungseigenschaften
production (ISO 4037-1:2019) und Erzeugungsmethoden (ISO 4037-1:2019)
This European Standard was approved by CEN on 18 January 2021.

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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4037-1:2021 E
worldwide for CEN national Members.

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SIST EN ISO 4037-1:2021
EN ISO 4037-1:2021 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 4037-1:2021
EN ISO 4037-1:2021 (E)
European foreword
The text of ISO 4037-1:2019 has been prepared by Technical Committee ISO/TC 85 "Nuclear energy,
nuclear technologies, and radiological protection” of the International Organization for Standardization
(ISO) and has been taken over as EN ISO 4037-1:2021 by Technical Committee CEN/TC 430 “Nuclear
energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by August 2021, and conflicting national standards shall
be withdrawn at the latest by August 2021.
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.
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 4037-1:2019 has been approved by CEN as EN ISO 4037-1:2021 without any
modification.

3

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SIST EN ISO 4037-1:2021

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SIST EN ISO 4037-1:2021
INTERNATIONAL ISO
STANDARD 4037-1
Second edition
2019-01
Radiological protection — X and
gamma reference radiation for
calibrating dosemeters and doserate
meters and for determining their
response as a function of photon
energy —
Part 1:
Radiation characteristics and
production methods
Radioprotection — Rayonnements X et gamma de référence
pour l'étalonnage des dosimètres et des débitmètres, et pour la
détermination de leur réponse en fonction de l'énergie des photons —
Partie 1: Caractéristiques des rayonnements et méthodes de
production
Reference number
ISO 4037-1:2019(E)
©
ISO 2019

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SIST EN ISO 4037-1:2021
ISO 4037-1:2019(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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

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SIST EN ISO 4037-1:2021
ISO 4037-1:2019(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 3
3 Terms and definitions . 3
4 Continuous reference filtered X radiation . 7
4.1 General . 7
4.1.1 Realisation of reference radiation fields . 7
4.1.2 Basis of conversion coefficients . 7
4.1.3 Radiation quality. 8
4.1.4 Choice of reference radiation . 8
4.2 Conditions and methods for producing reference X radiation .13
4.2.1 Characteristics of the high voltage generator .13
4.2.2 Tube potential and protective resistor .14
4.2.3 Filtration .15
4.2.4 Limitations concerning matched fields .19
4.2.5 X radiation shutter .20
4.2.6 Beam aperture .20
4.3 Field uniformity and scattered radiation .20
4.3.1 Field diameter .20
4.3.2 Field uniformity .20
4.3.3 Scattered radiation . .20
4.4 Summary of the requirements for reference X radiation fields .21
4.5 Validation of reference X radiation .21
4.5.1 General.21
4.5.2 Criteria for validation by HVL determination .22
4.5.3 Apparatus for HVL measurement .23
4.5.4 HVL measurement procedure .24
4.5.5 Criteria for validation by dosimetry . .24
4.5.6 Criteria for validation by spectrometry .24
5 Gamma radiation emitted by radionuclides .25
5.1 General .25
5.2 Radionuclides used for the production of gamma radiation .25
5.3 Specification of radiation sources .25
5.3.1 Sources .25
5.3.2 Encapsulation .26
5.4 Irradiation facility and influence of scattered radiation .26
5.4.1 General requirements .26
5.4.2 Collimated geometry installation .26
5.4.3 Variation of air kerma rate by means of lead attenuators .27
5.5 Checking installation conformity .27
6 Photon radiation with energies between 4 MeV and 9 MeV .28
6.1 General .28
6.2 Production of reference radiation .28
6.2.1 General.28
16 19 16
6.2.2 Photon reference radiation from de-excitation of O in the F(p, αγ) O
reaction .28
12
6.2.3 Photon reference radiation from de-excitation of C .30
6.3 Beam diameter and uniformity of radiation field .31
6.4 Contamination of photon reference radiation .31
6.4.1 General.31
© ISO 2019 – All rights reserved iii

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SIST EN ISO 4037-1:2021
ISO 4037-1:2019(E)

6.4.2 Contamination of reference radiation common to all methods of
production of reference radiation .32
6.4.3 Additional contamination of accelerator produced reference radiation
16
from de-excitation of O .32
Annex A (informative) Fluorescence X radiation with not enough information for matched
or characterized fields .33
241
Annex B (informative) Gamma radiation emitted by Am radionuclide with not enough
information for matched or characterized fields .40
Annex C (informative) Continuous filtered X radiation based on the quality index .42
Bibliography .45
iv © ISO 2019 – All rights reserved

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SIST EN ISO 4037-1:2021
ISO 4037-1:2019(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 4037-1:1996), which has been technically
revised. The main changes are:
— introduction of two types of reference fields, matched reference fields and characterized
reference fields;
— introduction of validation for matched reference fields;
— introduction of limits for the allowed deviation of parameters like high voltage, filter purity and
filter thickness from their nominal values. These limits now depend on the definition depth of the
phantom related quantity. This is done to achieve an overall uncertainty (k = 2) of about 6 % to 10 %
for the phantom related operational quantities.
A list of all the parts in the ISO 4037 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.
© ISO 2019 – All rights reserved v

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SIST EN ISO 4037-1:2021
ISO 4037-1:2019(E)

Introduction
This maintenance release of this document incorporates the improvements to high voltage generators
from 1996 to 2017 (e.g., the use of high frequency switching supplies providing nearly constant
potential), and the spectral measurements at irradiation facilities equipped with such generators
[4]
(e.g., the catalogue of X-ray spectra by Ankerhold ). It also incorporates all published information
with the aim to adjust the requirements for the technical parameters of the reference fields to the
targeted overall uncertainty of about 6 % to 10 % for the phantom related operational quantities of
[5]
the International Commission on Radiation Units and Measurements (ICRU) . It does not change the
general concept of the existing ISO 4037.
ISO 4037 focusing on photon reference radiation fields is divided into four parts. ISO 4037-1 gives the
methods of production and characterization of reference radiation fields in terms of the quantities
spectral photon fluence and air kerma free-in-air. ISO 4037-2 describes the dosimetry of the reference
radiation qualities in terms of air kerma and in terms of the phantom related operational quantities of
[5]
the International Commission on Radiation Units and Measurements (ICRU) . ISO 4037-3 describes
the methods for calibrating and determining the response of dosemeters and doserate meters in terms
[5]
of the phantom related operational quantities of the ICRU . ISO 4037-4 gives special considerations
and additional requirements for calibration of area and personal dosemeters in low energy X reference
radiation fields, which are reference fields with generating potential lower or equal to 30 kV.
The general procedures described in ISO 29661 are used as far as possible in this document. Also, the
symbols used are in line with ISO 29661.
vi © ISO 2019 – All rights reserved

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SIST EN ISO 4037-1:2021
INTERNATIONAL STANDARD ISO 4037-1:2019(E)
Radiological protection — X and gamma reference
radiation for calibrating dosemeters and doserate meters
and for determining their response as a function of photon
energy —
Part 1:
Radiation characteristics and production methods
1 Scope
This document specifies the characteristics and production methods of X and gamma reference
radiation for calibrating protection-level dosemeters and doserate meters with respect to the phantom
related operational quantities of the International Commission on Radiation Units and Measurements
[5] –1
(ICRU) . The lowest air kerma rate for which this standard is applicable is 1 µGy h . Below this air
kerma rate the (natural) background radiation needs special consideration and this is not included in
this document.
For the radiation qualities specified in Clauses 4 to 6, sufficient published information is available to
specify the requirements for all relevant parameters of the matched or characterized reference fields in
order to achieve the targeted overall uncertainty (k = 2) of about 6 % to 10 % for the phantom related
operational quantities. The X ray radiation fields described in the informative Annexes A to C are not
designated as reference X-radiation fields.
NOTE The first edition of ISO 4037-1, issued in 1996, included some additional radiation qualities for
which such published information is not available. These are fluorescent radiations, the gamma radiation of the
241
radionuclide Am, S-Am, and the high energy photon radiations R-Ti and R-Ni, which have been removed from
the main part of this document. The most widely used radiations, the fluorescent radiations and the gamma
241
radiation of the radionuclide Am, S-Am, are included nearly unchanged in the informative Annexes A and B.
The informative Annex C gives additional X radiation fields, which are specified by the quality index.
The methods for producing a group of reference radiations for a particular photon-energy range are
described in Clauses 4 to 6, which define the characteristics of these radiations. The three groups of
reference radiation are:
a) in the energy range from about 8 keV to 330 keV, continuous filtered X radiation;
b) in the energy range 600 keV to 1,3 MeV, gamma radiation emitted by radionuclides;
c) in the energy range 4 MeV to 9 MeV, photon radiation produced by accelerators.
The reference radiation field most suitable for the intended application can be selected from Table 1,
which gives an overview of all reference radiation qualities specified in Clauses 4 to 6. It does not
include the radiations specified in the Annexes A, B and C.
The requirements and methods given in Clauses 4 to 6 are targeted at an overall uncertainty (k = 2) of
the dose(rate) value of about 6 % to 10 % for the phantom related operational quantities in the reference
fields. To achieve this, two production methods are proposed:
The first one is to produce “matched reference fields”, whose properties are sufficiently well-
characterized so as to allow the use of the conversion coefficients recommended in ISO 4037-3.
The existence of only a small difference in the spectral distribution of the “matched reference field”
compared to the nominal reference field is validated by procedures, which are given and described in
detail in ISO 4037-2. For matched reference radiation fields, recommended conversion coefficients are
given in ISO 4037-3 only for specified distances between source and dosemeter, e.g., 1,0 m and 2,5 m.
© ISO 2019 – All rights reserved 1

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SIST EN ISO 4037-1:2021
ISO 4037-1:2019(E)

For other distances, the user has to decide if these conversion coefficients can be used. If both values
are very similar, e.g., differ only by 2 % or less, then a linear interpolation may be used.
The second method is to produce “characterized reference fields”. Either this is done by determining
the conversion coefficients using spectrometry, or the required value is measured directly using
secondary standard dosimeters. This method applies to any radiation quality, for any measuring
quantity and, if applicable, for any phantom and angle of radiation incidence. In addition, the
requirements on the parameters specifying the reference radiations depend on the definition depth in
the phantom, i.e., 0,07 mm, 3 mm and 10 mm, therefore, the requirements are different for the different
depths. Thus, a given radiation field can be a "matched reference field" for the depth of 0,07 mm but
not for the depth of 10 mm, for which it can then be a “characterized reference field”. The conversion
coefficients can be determined for any distance, provided the air kerma rate is not below 1 µGy/h.
Both methods need charged particle equilibrium for the reference field. However, this is not always
established in the workplace field for which the dosemeter is calibrated. This is especially true
at photon energies without inherent charged particle equilibrium at the reference depth d, which
depends on the actual combination of energy and reference depth d. Electrons of energies above 65 keV,
0,75 MeV and 2,1 MeV can just penetrate 0,07 mm, 3 mm and 10 mm of ICRU tissue, respectively, and
the radiation qualities with photon energies above these values are considered as radiation qualities
without inherent charged particle equilibrium for the quantities defined at these depths.
To determine the dose(rate) value and the associated overall uncertainty of it, a calibration of all
measuring instruments used for the determination of the quantity value is needed which is traceable to
national standards.
This document does not specify pulsed reference radiation fields.
Table 1 — List of X and gamma reference radiation, their mean energies, E Φ , for 1 m distance
()
and their short names
Radiation Radiation Radiation Radiation
E Φ E Φ E Φ E Φ
() () () ()
quality quality quality quality

keV keV keV keV
L-10 9,0 N-10 8,5 W-30 22,9 H-10 8,0
L-20 17,3 N-15 12,4 W-40 29,8 H-20 13,1
L-30 26,7 N-20 16,3 W-60 44,8 H-30 19,7
L-35 30,4 N-25 20,3 W-80 56,5 H-40 25,4
L-55 47,8 N-30 24,6 W-110 79,1 H-60 38,0
L-70 60,6 N-40 33,3 W-150 104 H-80 48,8
L-100 86,8 N-60 47,9 W-200 138 H-100 57,3
L-125 109 N-80 65,2 W-250 172 H-150 78,0
L-170 149 N-100 83,3 W-300 205 H-200 99,3
L-210 185 N-120 100 H-250 122
L-240 211 N-150 118 H-280 145
 N-200 165 H-300 143
 N-250 207 H-350 167
 N-300 248 H-400 190
 N-350 288
 N-400 328
2 © ISO 2019 – All rights reserved

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Table 1 (continued)
Radionuclides High energy photon radiations
Radiation Radionuclide Radiation Reaction
E Φ  
() E Φ EH*10
() ()
 
quality quality a

;
keV
MeV
137 12 12
S-Cs Cs 662 R-C C (p,p'γ)
...

SLOVENSKI STANDARD
oSIST prEN ISO 4037-1:2020
01-december-2020
Radiološka zaščita - Referenčno sevanje z rentgenskimi in gama žarki za
kalibracijo dozimetrov in merilnikov doze sevanja ter za ugotavljanje njihovega
odzivanja kot funkcije fotonske energije - 1. del: Značilnosti sevanja in proizvodne
metode (ISO 4037-1:2019)
Radiological protection - X and gamma reference radiation for calibrating dosemeters
and doserate meters and for determining their response as a function of photon energy -
Part 1: Radiation characteristics and production methods (ISO 4037-1:2019)
Strahlenschutz - Röntgen- und Gamma-Referenzstrahlungsfelder zur Kalibrierung von
Dosimetern und Dosisleistungsmessgeräten und zur Bestimmung ihres
Ansprechvermögens als Funktion der Photonenenergie - Teil 1: Strahlungseigenschaften
und Erzeugungsmethoden
Radioprotection - Rayonnements X et gamma de référence pour l'étalonnage des
dosimètres et des débitmètres, et pour la détermination de leur réponse en fonction de
l'énergie des photons - Partie 1: Caractéristiques des rayonnements et méthodes de
production (ISO 4037-1:2019)
Ta slovenski standard je istoveten z: prEN ISO 4037-1
ICS:
17.240 Merjenje sevanja Radiation measurements
oSIST prEN ISO 4037-1:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 4037-1:2020

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oSIST prEN ISO 4037-1:2020
INTERNATIONAL ISO
STANDARD 4037-1
Second edition
2019-01
Radiological protection — X and
gamma reference radiation for
calibrating dosemeters and doserate
meters and for determining their
response as a function of photon
energy —
Part 1:
Radiation characteristics and
production methods
Radioprotection — Rayonnements X et gamma de référence
pour l'étalonnage des dosimètres et des débitmètres, et pour la
détermination de leur réponse en fonction de l'énergie des photons —
Partie 1: Caractéristiques des rayonnements et méthodes de
production
Reference number
ISO 4037-1:2019(E)
©
ISO 2019

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oSIST prEN ISO 4037-1:2020
ISO 4037-1:2019(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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

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oSIST prEN ISO 4037-1:2020
ISO 4037-1:2019(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 3
3 Terms and definitions . 3
4 Continuous reference filtered X radiation . 7
4.1 General . 7
4.1.1 Realisation of reference radiation fields . 7
4.1.2 Basis of conversion coefficients . 7
4.1.3 Radiation quality. 8
4.1.4 Choice of reference radiation . 8
4.2 Conditions and methods for producing reference X radiation .13
4.2.1 Characteristics of the high voltage generator .13
4.2.2 Tube potential and protective resistor .14
4.2.3 Filtration .15
4.2.4 Limitations concerning matched fields .19
4.2.5 X radiation shutter .20
4.2.6 Beam aperture .20
4.3 Field uniformity and scattered radiation .20
4.3.1 Field diameter .20
4.3.2 Field uniformity .20
4.3.3 Scattered radiation . .20
4.4 Summary of the requirements for reference X radiation fields .21
4.5 Validation of reference X radiation .21
4.5.1 General.21
4.5.2 Criteria for validation by HVL determination .22
4.5.3 Apparatus for HVL measurement .23
4.5.4 HVL measurement procedure .24
4.5.5 Criteria for validation by dosimetry . .24
4.5.6 Criteria for validation by spectrometry .24
5 Gamma radiation emitted by radionuclides .25
5.1 General .25
5.2 Radionuclides used for the production of gamma radiation .25
5.3 Specification of radiation sources .25
5.3.1 Sources .25
5.3.2 Encapsulation .26
5.4 Irradiation facility and influence of scattered radiation .26
5.4.1 General requirements .26
5.4.2 Collimated geometry installation .26
5.4.3 Variation of air kerma rate by means of lead attenuators .27
5.5 Checking installation conformity .27
6 Photon radiation with energies between 4 MeV and 9 MeV .28
6.1 General .28
6.2 Production of reference radiation .28
6.2.1 General.28
16 19 16
6.2.2 Photon reference radiation from de-excitation of O in the F(p, αγ) O
reaction .28
12
6.2.3 Photon reference radiation from de-excitation of C .30
6.3 Beam diameter and uniformity of radiation field .31
6.4 Contamination of photon reference radiation .31
6.4.1 General.31
© ISO 2019 – All rights reserved iii

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6.4.2 Contamination of reference radiation common to all methods of
production of reference radiation .32
6.4.3 Additional contamination of accelerator produced reference radiation
16
from de-excitation of O .32
Annex A (informative) Fluorescence X radiation with not enough information for matched
or characterized fields .33
241
Annex B (informative) Gamma radiation emitted by Am radionuclide with not enough
information for matched or characterized fields .40
Annex C (informative) Continuous filtered X radiation based on the quality index .42
Bibliography .45
iv © ISO 2019 – All rights reserved

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oSIST prEN ISO 4037-1:2020
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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 4037-1:1996), which has been technically
revised. The main changes are:
— introduction of two types of reference fields, matched reference fields and characterized
reference fields;
— introduction of validation for matched reference fields;
— introduction of limits for the allowed deviation of parameters like high voltage, filter purity and
filter thickness from their nominal values. These limits now depend on the definition depth of the
phantom related quantity. This is done to achieve an overall uncertainty (k = 2) of about 6 % to 10 %
for the phantom related operational quantities.
A list of all the parts in the ISO 4037 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.
© ISO 2019 – All rights reserved v

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Introduction
This maintenance release of this document incorporates the improvements to high voltage generators
from 1996 to 2017 (e.g., the use of high frequency switching supplies providing nearly constant
potential), and the spectral measurements at irradiation facilities equipped with such generators
[4]
(e.g., the catalogue of X-ray spectra by Ankerhold ). It also incorporates all published information
with the aim to adjust the requirements for the technical parameters of the reference fields to the
targeted overall uncertainty of about 6 % to 10 % for the phantom related operational quantities of
[5]
the International Commission on Radiation Units and Measurements (ICRU) . It does not change the
general concept of the existing ISO 4037.
ISO 4037 focusing on photon reference radiation fields is divided into four parts. ISO 4037-1 gives the
methods of production and characterization of reference radiation fields in terms of the quantities
spectral photon fluence and air kerma free-in-air. ISO 4037-2 describes the dosimetry of the reference
radiation qualities in terms of air kerma and in terms of the phantom related operational quantities of
[5]
the International Commission on Radiation Units and Measurements (ICRU) . ISO 4037-3 describes
the methods for calibrating and determining the response of dosemeters and doserate meters in terms
[5]
of the phantom related operational quantities of the ICRU . ISO 4037-4 gives special considerations
and additional requirements for calibration of area and personal dosemeters in low energy X reference
radiation fields, which are reference fields with generating potential lower or equal to 30 kV.
The general procedures described in ISO 29661 are used as far as possible in this document. Also, the
symbols used are in line with ISO 29661.
vi © ISO 2019 – All rights reserved

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oSIST prEN ISO 4037-1:2020
INTERNATIONAL STANDARD ISO 4037-1:2019(E)
Radiological protection — X and gamma reference
radiation for calibrating dosemeters and doserate meters
and for determining their response as a function of photon
energy —
Part 1:
Radiation characteristics and production methods
1 Scope
This document specifies the characteristics and production methods of X and gamma reference
radiation for calibrating protection-level dosemeters and doserate meters with respect to the phantom
related operational quantities of the International Commission on Radiation Units and Measurements
[5] –1
(ICRU) . The lowest air kerma rate for which this standard is applicable is 1 µGy h . Below this air
kerma rate the (natural) background radiation needs special consideration and this is not included in
this document.
For the radiation qualities specified in Clauses 4 to 6, sufficient published information is available to
specify the requirements for all relevant parameters of the matched or characterized reference fields in
order to achieve the targeted overall uncertainty (k = 2) of about 6 % to 10 % for the phantom related
operational quantities. The X ray radiation fields described in the informative Annexes A to C are not
designated as reference X-radiation fields.
NOTE The first edition of ISO 4037-1, issued in 1996, included some additional radiation qualities for
which such published information is not available. These are fluorescent radiations, the gamma radiation of the
241
radionuclide Am, S-Am, and the high energy photon radiations R-Ti and R-Ni, which have been removed from
the main part of this document. The most widely used radiations, the fluorescent radiations and the gamma
241
radiation of the radionuclide Am, S-Am, are included nearly unchanged in the informative Annexes A and B.
The informative Annex C gives additional X radiation fields, which are specified by the quality index.
The methods for producing a group of reference radiations for a particular photon-energy range are
described in Clauses 4 to 6, which define the characteristics of these radiations. The three groups of
reference radiation are:
a) in the energy range from about 8 keV to 330 keV, continuous filtered X radiation;
b) in the energy range 600 keV to 1,3 MeV, gamma radiation emitted by radionuclides;
c) in the energy range 4 MeV to 9 MeV, photon radiation produced by accelerators.
The reference radiation field most suitable for the intended application can be selected from Table 1,
which gives an overview of all reference radiation qualities specified in Clauses 4 to 6. It does not
include the radiations specified in the Annexes A, B and C.
The requirements and methods given in Clauses 4 to 6 are targeted at an overall uncertainty (k = 2) of
the dose(rate) value of about 6 % to 10 % for the phantom related operational quantities in the reference
fields. To achieve this, two production methods are proposed:
The first one is to produce “matched reference fields”, whose properties are sufficiently well-
characterized so as to allow the use of the conversion coefficients recommended in ISO 4037-3.
The existence of only a small difference in the spectral distribution of the “matched reference field”
compared to the nominal reference field is validated by procedures, which are given and described in
detail in ISO 4037-2. For matched reference radiation fields, recommended conversion coefficients are
given in ISO 4037-3 only for specified distances between source and dosemeter, e.g., 1,0 m and 2,5 m.
© ISO 2019 – All rights reserved 1

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oSIST prEN ISO 4037-1:2020
ISO 4037-1:2019(E)

For other distances, the user has to decide if these conversion coefficients can be used. If both values
are very similar, e.g., differ only by 2 % or less, then a linear interpolation may be used.
The second method is to produce “characterized reference fields”. Either this is done by determining
the conversion coefficients using spectrometry, or the required value is measured directly using
secondary standard dosimeters. This method applies to any radiation quality, for any measuring
quantity and, if applicable, for any phantom and angle of radiation incidence. In addition, the
requirements on the parameters specifying the reference radiations depend on the definition depth in
the phantom, i.e., 0,07 mm, 3 mm and 10 mm, therefore, the requirements are different for the different
depths. Thus, a given radiation field can be a "matched reference field" for the depth of 0,07 mm but
not for the depth of 10 mm, for which it can then be a “characterized reference field”. The conversion
coefficients can be determined for any distance, provided the air kerma rate is not below 1 µGy/h.
Both methods need charged particle equilibrium for the reference field. However, this is not always
established in the workplace field for which the dosemeter is calibrated. This is especially true
at photon energies without inherent charged particle equilibrium at the reference depth d, which
depends on the actual combination of energy and reference depth d. Electrons of energies above 65 keV,
0,75 MeV and 2,1 MeV can just penetrate 0,07 mm, 3 mm and 10 mm of ICRU tissue, respectively, and
the radiation qualities with photon energies above these values are considered as radiation qualities
without inherent charged particle equilibrium for the quantities defined at these depths.
To determine the dose(rate) value and the associated overall uncertainty of it, a calibration of all
measuring instruments used for the determination of the quantity value is needed which is traceable to
national standards.
This document does not specify pulsed reference radiation fields.
Table 1 — List of X and gamma reference radiation, their mean energies, E Φ , for 1 m distance
()
and their short names
Radiation Radiation Radiation Radiation
E Φ E Φ E Φ E Φ
() () () ()
quality quality quality quality

keV keV keV keV
L-10 9,0 N-10 8,5 W-30 22,9 H-10 8,0
L-20 17,3 N-15 12,4 W-40 29,8 H-20 13,1
L-30 26,7 N-20 16,3 W-60 44,8 H-30 19,7
L-35 30,4 N-25 20,3 W-80 56,5 H-40 25,4
L-55 47,8 N-30 24,6 W-110 79,1 H-60 38,0
L-70 60,6 N-40 33,3 W-150 104 H-80 48,8
L-100 86,8 N-60 47,9 W-200 138 H-100 57,3
L-125 109 N-80 65,2 W-250 172 H-150 78,0
L-170 149 N-100 83,3 W-300 205 H-200 99,3
L-210 185 N-120 100 H-250 122
L-240 211 N-150 118 H-280 145
 N-200 165 H-300 143
 N-250 207 H-350 167
 N-300 248 H-400 190
 N-350 288
 N-400 328
2 © ISO 2019 – All rights reserved

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Table 1 (continued)
Radionuclides High energy photon radiations
Radiation Radionuclide Radiation Reaction
E Φ  
() E Φ EH*10
() ()
 
quality quality a

;
keV
MeV
137 12 12
S-Cs Cs 662 R-C C (p,p'γ) C 4,2; 4,4
60 19 16
S-Co Co 1250 R-F F (p,αγ) O 4,4; 6,5
NOTE  In the informative Annexes A to C, further radiation qualities are given. These cover the mean photon
energies from 8 keV up to 270 keV.
a
  Mean photon energy weighted by distribution of ambient dose equivalent, H*(10), with respect to photon energy E.
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 2919, Radiological protection — Sealed radioactive sources — General requirements and classification
ISO 4037-2:2018, Radiological protection — X and gamma reference radiation for calibrating dosemeters
and doserate meters and for determining their response as a function of photon energy — Part 2: Dosimetry
for radiological protection over the energy ranges 8 keV to 1,3 MeV and 4 MeV to 9 MeV
ISO 4037-3, Radiological protection — X and gamma reference radiation for calibrating dosemeters and
doserate meters and for determining their response as a function of photon energy — Part 3: Calibration of
area and personal dosemeters and the measurement of their response as a function of energy and angle of
incidence
ISO 29661, Reference radiation fields for radiation protection — Definitions and fundamental concepts
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 29661 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
air kerma-to-dose-equivalent conversion coefficient
h
K
quotient of the dose equivalent, H, and the air kerma free-in-air, K , at a point in the photon radiation field
a
H
h =
K
K
a
–1
Note 1 to entry: The unit of the air kerma-to-dose-equivalent conversion coefficient is sievert per gray (Sv·Gy ).
Note 2 to entry: This definition differs from the one given by ISO 29661:2012, 3.2.4, as it uses the air kerma
instead of the air collision kerma. See also 4.1.2.
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Note 3 to entry: The full specification of an air kerma-to-dose-equivalent conversion coefficient includes the
specification of the type of dose equivalent, e.g. ambient, directional or personal. The conversion coefficient, h ,
K
 
depends on the energy and, for H (10), H (3), H (0,07), H'(3, ) and H'(0,07,  ), also on the directional
p p p
distribution of the incident radiation. It is, therefore, useful to consider the conversion coefficient as a function,
h (E, α), of the energy, E, of monoenergetic photons at several angles of incidence α.
K
Note 4 to entry: The conversion coefficients from the air kerma free-in-air, K , to H'(0,07), to H'(3), to H*(10),
a
to H (10), to H (3) or to H (0,07) for the radiation quality U and the angle of incidence α are indicated as
p p p
h' (0,07; U, α), h' (3; U, α), h* (10; U), h (10; U, α), h (3; U, α), and h (0,07; U, α), respectively.
K K K pK pK pK
3.2
characterized reference radiation field
reference radiation field whose properties are not sufficiently well-characterized so as to allow the use
of recommended conversion coefficients but the mean energy of which is close enough to the nominal
value to be used as a reference radiation field with the given designation
Note 1 to entry: Either this is done by determining the conversion coefficients using spectrometry, or the
required value is measured directly using secondary standard dosimeters.
3.3
effective energy (of radiation comprised of X-rays with a range of energies)
E
eff
energy of the monoenergetic photons which have the same first HVL
3.4
generating potential
U
gen
potential difference between positive and negative output of the high voltage generator
3.5
half-value thickness
half-value layer
HVL
thickness of the attenuating layer that reduces the quantity of interest of a unidirectional beam of
infinitesimal width to half of its initial value
[SOURCE: ISO 80000-10:—, 10.53]
Note 1 to entry: For this document, the quantity of interest is the air kerma.
Note 2 to entry: In this definition, the contribution of all
...